GnRH analogs induce a LH peak and increase pregnancy per timed-AI in ewes.

To date, there have been no studies testing the capacity of GnRH analogs and respective doses to induce a LH peak in sheep. In this sense, the present study aimed to evaluate the capacity of different synthetic forms and doses of GnRH in inducing LH release in sheep, and the effect of GnRH administration at timed artificial insemination (TAI) on pregnancy per timed-AI. In experiment 1, ewes (n = 40) received an intravaginal device (IVD) of medroxyprogesterone acetate (MPA; 60 mg) for 7 d and prostaglandin F2α analog on Day 5. On Day 7, the ewes were allocated randomly into one of eight groups (n = 5/group), which received a GnRH analog at a specific dose, as follows: lecirelin (12.5 or 25 µg), gonadorelin (50 or 100 µg), buserelin acetate (4.2 or 8.4 µg), or deslorelin (375 or 750 µg). Blood samples for LH determination were obtained at 0, 2, 4, and 6 h after GnRH and the IVDs were removed after the last blood collection. The maximal LH concentration induced by gonadorelin at doses of 50 µg and 100 µg (12.0 ± 2.4 ng/mL and 28.6 ± 7.1 ng/mL, respectively) was lower (P < 0.05) than serum LH induced by 8.4 µg of buserelin (78.9 ± 12.9 ng/mL), 375 µg and 750 µg of deslorelin (75.6 ± 7.4 ng/mL and 72.1 ± 10.6 ng/mL, respectively) and 12.5 µg and 25 µg of lecirelin (73.3 ± 17.8 ng/mL and 61.6 ± 5.9 ng/mL, respectively). However, the maximal LH concentration induced by 4.2 µg of buserelin (49.4 ± 5.9 ng/mL) was similar (P > 0.05) to the 100 µg of gonadorelin. The total release of LH (area under the curve - AUC) after treatment with 50 µg of gonadorelin (31.7 ± 5.9 ng h/mL) was lower (P < 0.05) than after other agonists. In a second experiment, 330 ewes were treated with IVD containing MPA for 7 d. Simultaneously with IVD removal, 250 µg of cloprostenol and 200 IU of eCG were administered. Then, ewes were assigned randomly to either no further treatment (control); or to receive 4.2 µg of buserelin acetate (GnRH group) at cervical TAI, which was performed with fresh semen 54 h after IVD withdrawal in all the animals. Higher pregnancy per timed-AI was observed for GnRH (50.3 %) compared to control (40.7 %). We conclude that buserelin acetate (8.4 µg), lecirelin (12.5 and 25 µg) and deslorelin (375 and 750 µg) induced a greater stimulatory effect on LH secretion than gonadorelin treatment. Furthermore, buserelin acetate treatment at TAI increased pregnancy per timed-AI in ewes previously treated with MPA and eCG.

Effects of prostaglandin analogs on blood flow velocity and resistance in the ophthalmic artery of rabbits.

PURPOSE: The aim of this study was to investigate the effects of prostaglandin analogs on blood flow in the ophthalmic artery of clinically healthy rabbits. METHODS: Fifty-five clinically healthy New Zealand white rabbits were divided into six groups, and the left eyes were treated for four weeks with the preservative benzalkonium chloride (BAK) only or a topical formulation of different prostaglandin analogs (bimatoprost BAK, tafluprost BAK-free, travoprost BAK, travoprost POLYQUAD, and latanoprost BAK). Color Doppler imaging was performed before and after the treatments. The mean values of the peak systolic velocity (PSV) and end diastolic velocity and the resistive index (RI) were calculated. Statistical analysis was performed to compare the differences pre- and post-treatment for each drug and post-treatment among the drugs. RESULTS: The prostaglandin analogs did not affect PSV. Bimatoprost BAK, travoprost POLYQUAD, and latanoprost BAK did not change RI. Tafluprost BAK-free and travoprost BAK therapy resulted in similar reductions in RI. No significant differences pre- and post-treatment were found when BAK was administered alone. CONCLUSION: The prostaglandin analogs tafluprost BAK-free and travoprost BAK improved blood flow in the ophthalmic artery in healthy New Zealand white rabbits, which suggests that these drugs enhance the prevention of the progression the progression of glaucoma.

Effects of prostaglandin analogs on blood flow velocity and resistance in the ophthalmic artery of rabbits / Efeitos dos análogos da prostaglandina na velocidade do fluxo sanguíneo e resistência na artéria oftálmica de coelhos

ABSTRACT Purpose: The aim of this study was to investigate the effects of prostaglandin analogs on blood flow in the ophthalmic artery of clinically healthy rabbits. Methods: Fifty-five clinically healthy New Zealand white rabbits were divided into six groups, and the left eyes were treated for four weeks with the preservative benzalkonium chloride (BAK) only or a topical formulation of different prostaglandin analogs (bimatoprost BAK, tafluprost BAK-free, travoprost BAK, travoprost POLYQUAD, and latanoprost BAK). Color Doppler imaging was performed before and after the treatments. The mean values of the peak systolic velocity (PSV) and end diastolic velocity and the resistive index (RI) were calculated. Statistical analysis was performed to compare the differences pre- and post-treatment for each drug and post-treatment among the drugs. Results: The prostaglandin analogs did not affect PSV. Bimatoprost BAK, travoprost POLYQUAD, and latanoprost BAK did not change RI. Tafluprost BAK-free and travoprost BAK therapy resulted in similar reductions in RI. No significant differences pre- and post-treatment were found when BAK was administered alone. Conclusion: The prostaglandin analogs tafluprost BAK-free and travoprost BAK improved blood flow in the ophthalmic artery in healthy New Zealand white rabbits, which suggests that these drugs enhance the prevention of the progression the progression of glaucoma.

RESUMO Objetivo: O objetivo deste estudo foi investigar os efeitos dos análogos da prostaglandina (PGAs) no fluxo sanguíneo da artéria oftálmica em coelhos. Métodos: Cinquenta e cinco coelhos da raça Nova Zelândia clinicamente saudáveis foram divididos em seis grupos para tratamento com formulação tópica de diferentes APGs (bimatoprosta BAK, tafluprosta BAK-free, travoprosta BAK, travoprosta POLYQUAD e latanoprosta BAK) e formulações contendo apenas o conservante cloreto de benzalcônio (BAK). Foi realizada ultrassonografia com Doppler antes e após os tratamentos. Os valores do pico da velocidade sistólica (PSV) e da velocidade diastólica final foram obtidos e o índice de resistência (RI) foi então calculado. A análise estatística foi realizada para comparar as diferenças entre cada droga no pré e pós-tratamento, além das diferenças no pós-tratamento entre as drogas. Resultados: Estes colírios PGAs não afetaram o PSV. A bimatoprosta com o conservante BAK, travoprosta com o conservante POLYQUAD e latanoprosta com o conservante BAK não alteraram o RI. Já o tratamento com tafluprosta sem conservante (BAK-free) e travoprosta com o conservante BAK promoveram redução similar dos valores do RI. Não houve diferença significativa na comparação entre valores pré e pós-tratamento quando BAK foi administrado isoladamente. Conclusão: Os PGAs tafluprosta BAK-free e travoprosta BAK melhoraram o fluxo sanguíneo na artéria oftálmica em coelhos da raça Nova Zelândia sugerindo que estes medicamentos possam contribuir na prevenção da progressão do glaucoma.

Effect of volume replacement during combined experimental hemorrhagic shock and traumatic brain injury in prostanoids, brain pathology and pupil status.

Traumatic brain injury (TBI) is the main cause of trauma-related deaths. Systemic hypotension and intracranial hypertension causes cerebral ischemia by altering metabolism of prostanoids. We describe prostanoid, pupilar and pathological response during resuscitation with hypertonic saline solution (HSS) in TBI. Method Fifteen dogs were randomized in three groups according to resuscitation after TBI (control group; lactated Ringer's (LR) group and HSS group), with measurement of thromboxane, prostaglandin, macroscopic and microscopic pathological evaluation and pupil evaluation.Result Concentration of prostaglandin is greater in the cerebral venous blood than in plasma and the opposite happens with concentration of thromboxane. Pathology revealed edema in groups with the exception of group treated with HSS.Discussion and conclusion There is a balance between the concentrations of prostaglandin and thromboxane. HSS prevented the formation of cerebral edema macroscopically detectable. Pupillary reversal occurred earlier in HSS group than in LR group.

Effect of volume replacement during combined experimental hemorrhagic shock and traumatic brain injury in prostanoids, brain pathology and pupil status / Efeito da reposição volêmica durante o choque hemorrágico combinado com traumatismo craniencefálico sobre prostanóides, patologia cerebral e status pupilar

Traumatic brain injury (TBI) is the main cause of trauma-related deaths. Systemic hypotension and intracranial hypertension causes cerebral ischemia by altering metabolism of prostanoids. We describe prostanoid, pupilar and pathological response during resuscitation with hypertonic saline solution (HSS) in TBI. Method Fifteen dogs were randomized in three groups according to resuscitation after TBI (control group; lactated Ringer’s (LR) group and HSS group), with measurement of thromboxane, prostaglandin, macroscopic and microscopic pathological evaluation and pupil evaluation.Result Concentration of prostaglandin is greater in the cerebral venous blood than in plasma and the opposite happens with concentration of thromboxane. Pathology revealed edema in groups with the exception of group treated with HSS.Discussion and conclusion There is a balance between the concentrations of prostaglandin and thromboxane. HSS prevented the formation of cerebral edema macroscopically detectable. Pupillary reversal occurred earlier in HSS group than in LR group.

O traumatismo cranioencefálico (TCE) é a principal causa de morte relacionada ao trauma. O choque hemorrágico e hipertensão intracraniana causam isquemia cerebral alterando o metabolismo de prostanóides. Neste estudo, relatamos o comportamento dos prostanóides, resposta pupilar e patologia durante a reposição volêmica com solução salina hipertônica (SSH) no TCE. Método Quinze cachorros foram randomizados em três grupos (controle, grupo de Ringer lactato e grupo de SSH) e foram avaliados tromboxane, prostaglandina, avaliação patológica macroscópica e microscópica e status pupilar.Resultado A concentração de prostaglandina é maior no sangue cerebral em comparação ao plasma, e o inverso ocorre com o tromboxane. A patologia revelou edema em todos os grupos, com exceção do grupo tratado com SSH.Discussão e conclusão Existe um equilíbrio entre concentrações cerebrais e plasmáticas de prostaglandina e tromboxane. A SSH protegeu o cérebro da formação de edema pós traumático.

Mutations in COL27A1 cause Steel syndrome and suggest a founder mutation effect in the Puerto Rican population.

Osteochondrodysplasias represent a large group of developmental structural disorders that can be caused by mutations in a variety of genes responsible for chondrocyte development, differentiation, mineralization and early ossification. The application of whole-exome sequencing to disorders apparently segregating as Mendelian traits has proven to be an effective approach to disease gene identification for conditions with unknown molecular etiology. We identified a homozygous missense variant p.(Gly697Arg) in COL27A1, in a family with Steel syndrome and no consanguinity. Interestingly, the identified variant seems to have arisen as a founder mutation in the Puerto Rican population.

Effects and mechanisms of Fenofibrate on the secretion of vascular endothelial contraction factors in hypertensive rats.

This study investigated the effects of the peroxisome proliferator-activated receptor alpha (PPAR-α) agonist, Fenofibrate, on the secretion of vascular endothelial contraction factors in hypertensive rats to elucidate its possible mechanisms. The vascular ring contraction experiment was used to observe whether rat vascular tension of clean grade spontaneously hypertensive rats (SHR) changes after 1-h incubation of 0.1, 1.0, 10.0 µM Fenofibrate with 10.0 µM Fenofibrate, a PPAR-α antagonist (MK866), and a PPAR-γ antagonist (GW9662) in SHR. The results were compared with Wistar Kyoto rats. Enzyme-linked immunosorbent assay was used to detect the secretion of the serum vascular endothelial contraction factor prostacyclin-1α (PGF-1α), PGF-2α, and thromboxane B2 (TXB2). Western blot was used to detect COX-1 protein expression. A quantity of 10.0 µM Fenofibrate significantly reduced vasoconstriction in SHR compared to the control group (P = 0.013). The PPAR-α antagonist, MK866, significantly improved the vascular contractility of SHR when incubated with 10.0 µM Fenofibrate (P = 0.021). The PPAR-γ antagonist, GW9662, had no significant effect on the vascular contractility of SHR when incubated with 10.0 µM Fenofibrate (P = 0.071). The isolated aorta of SHR released significantly lower PGF- 1α (P = 0.014), PGF-2α (P = 0.023), and TXB2 (P = 0.017) levels in the 10.0 µM Fenofibrate group compared to the control group. COX-1 expression of SHR rat vascular endothelium was significantly depressed in the 10.0 µM Fenofibrate group compared to the control group (P = 0.027). In conclusion, Fenofibrate reduces the secretion of vascular endothelial contraction factors in hypertensive rats, which might arise through the endothelium influencing COX-1 expression.

Eyelash growth induced by topical prostaglandin analogues, bimatoprost, tafluprost, travoprost, and latanoprost in rabbits.

PURPOSE: Prostaglandin analogues (PGA) are ocular hypotensive agents used for the treatment of glaucoma. Hypertrichosis of the eyelashes has been reported in humans as a side effect. Eyelash growth was investigated with clinical trials in people using bimatoprost. Scattered reports of eyelash growth during the treatment of glaucoma with other PGA are also found in the literature. We investigated the effect of 4 different topical PGA on eyelash length. METHODS: Forty New Zealand white rabbits were divided into 4 groups and received daily topical application of bimatoprost, tafluprost, travoprost, and latanoprost in the left eye for 4 weeks. The right eye received no treatment. Eyelash length was measured in both eyes before and after treatment using a stainless steel digital caliper. RESULTS: Bimatoprost and tafluprost groups had significant increases in eyelash length. We did not observe significant eyelash growth in rabbits receiving travoprost and latanoprost after 1 month of treatment. CONCLUSIONS: Today, only bimatoprost is approved for growing eyelashes, and our research shows that tafluprost could be further explored by the cosmetic and pharmaceutical industry. Additional research using travoprost and latanoprost as agents for eyelash growth should be performed in the future using prolonged treatment periods to determine whether or not these PGA induce eyelash growth, and investigate other possible side effects.

Increased cyclooxygenase-2-derived prostanoids contributes to the hyperreactivity to noradrenaline in mesenteric resistance arteries from offspring of diabetic rats.

This study analyzed the effect of in utero exposure to maternal diabetes on contraction to noradrenaline in mesenteric resistance arteries (MRA) from adult offspring, focusing on the role of cyclooxygenase (COX)-derived prostanoids. Diabetes in the maternal rat was induced by a single injection of streptozotocin (50 mg/kg body weight) on day 7 of pregnancy. Contraction to noradrenaline was analyzed in isolated MRA from offspring of diabetic (O-DR) and non-diabetic (O-CR) rats at 3, 6 and 12 months of age. Release of thromboxane A(2) (TxA(2)) and prostaglandins E(2) (PGE(2)) and F(2α) (PGF(2α)), was measured by specific enzyme immunoassay kits. O-DR developed hypertension from 6 months of age compared with O-CR. Arteries from O-DR were hyperactive to noradrenaline only at 6 and 12 months of age. Endothelial removal abolished this hyperreactivity to noradrenaline between O-CR and O-DR. Preincubation with either the COX-1/2 (indomethacin) or COX-2 inhibitor (NS-398) decreased noradrenaline contraction only in 6- and 12-month-old O-DR, while it remained unmodified by COX-1 inhibitor SC-560. In vessels from 6-month-old O-DR, a similar reduction in the contraction to noradrenaline produced by NS-398 was observed when TP and EP receptors were blocked (SQ29548+AH6809). In 12-month-old O-DR, this effect was only achieved when TP, EP and FP were blocked (SQ29548+AH6809+AL8810). Noradrenaline-stimulated TxB(2) and PGE(2) release was higher in 6- and 12-month-old O-DR, whereas PGF(2α) was increased only in 12-month-old O-DR. Our results demonstrated that in utero exposure to maternal hyperglycaemia in rats increases the participation of COX-2-derived prostanoids on contraction to noradrenaline, which might help to explain the greater response to this agonist in MRA from 6- and 12-month-old offspring. As increased contractile response in resistance vessels may contribute to hypertension, our results suggest a role for these COX-2-derived prostanoids in elevating vascular resistance and blood pressure in offspring of diabetic rats.

The administration of exogenous prostaglandin may improve ovulation in pacu (Piaractus mesopotamicus).

Based on the reports of unsuccessful ovulation in pacu (Piaractus mesopotamicus) by fish farmers and researchers undertaking artificial reproduction programs, we evaluated the use of prostaglandin F (PGF) to improve pacu ovulation. This study was conducted during two spawning seasons (2009/2010 and 2010/2011) with two samplings in the first season and one sampling in the second season. A total of 45 females was sampled in this study. The control group was injected with carp pituitary extract (crude extract, 6 mg/kg), and the treatment group received PGF (2 mL per fish in the 2009/2010 season and 5 mL per fish in the 2010/2011 season) in addition to the crude extract. In both seasons, 100% (N = 4, 2009/2010 first sampling; N = 5, 2009/2010 second sampling; and N = 3, 2010/2011) of the PGF-treated fish spawned. In contrast, 53.0% (N = 9) and 83.3% (N = 10) of the control fish spawned in the first and second samplings of the 2009/2010 season, respectively, and only 25.0% (N = 1) spawned in the 2010/2011 season. Fecundity, fertility, and hatching rates did not differ (P > 0.05) between the treated and control fish. Based on oocyte volume frequency analysis, ovaries of the control fish had more (P < 0.05) vitellogenic oocytes with germinal vesicle breakdown that remained unovulated after spawning, whereas more (P < 0.05) of previtellogenic oocytes were present in the ovaries of the PGF-treated fish. In conclusion, administration of exogenous prostaglandin may improve the outcome of hormonally induced spawning in tropical migratory fish.

Neither plasma progesterone concentrations nor exogenous eCG affects rates of ovulation or pregnancy in fixed-time artificial insemination (FTAI) protocols for puberal Nellore heifers.

The objective was to evaluate the effects of plasma progesterone (P4) concentrations and exogenous eCG on ovulation and pregnancy rates of pubertal Nellore heifers in fixed-time artificial insemination (FTAI) protocols. In Experiment 1 (Exp. 1), on Day 0 (7 d after ovulation), heifers (n = 15) were given 2 mg of estradiol benzoate (EB) im and randomly allocated to receive: an intravaginal progesterone-releasing device containing 0.558 g of P4 (group 0.5G, n = 4); an intravaginal device containing 1 g of P4 (group 1G, n = 4); 0.558 g of P4 and PGF(2α) (PGF; 150 µg d-cloprostenol, group 0.5G/PGF, n = 4); or 1 g of P4 and PGF (group 1G/PGF, n = 3). On Day 8, PGF was given to all heifers and intravaginal devices removed; 24 h later (Day 9), all heifers were given 1 mg EB im. In Exp. 2, pubertal Nellore heifers (n = 292) were treated as in Exp. 1, with FTAI on Day 10 (30 to 36 h after EB). In Exp. 3, pubertal heifers (n = 459) received the treatments described for groups 0.5G/PGF and 1G/PGF and were also given 300 IU of eCG im (groups 0.5G/PGF/eCG and 1G/PGF/eCG) at device removal (Day 8). In Exp. 1, plasma P4 concentrations were significantly higher in heifers that received 1.0 vs 0.588 g P4, and were significantly lower in heifers that received PGF on Day 0. In Exp. 2 and 3, there were no significant differences among groups in rates of ovulation (65-77%) or pregnancy (Exp. 2: 26-33%; Exp. 3: 39-43%). In Exp. 3, diameter of the dominant ovarian follicle on Day 9 was larger in heifers given 0.558 g vs 1.0 g P4 (10.3 ± 0.2 vs 9.3 ± 0.2 mm; P < 0.01). In conclusion, lesser amounts of P4 in the intravaginal device or PGF on Day 0 decreased plasma P4 from Days 1 to 8 and increased diameter of the dominant follicle on Day 9. However, neither of these nor 300 IU of eCG on Day 8 significantly increased rates of ovulation or pregnancy.

Effect of fixed-time embryo transfer on reproductive efficiency in high-producing repeat-breeder Holstein cows.

The aim of the present study was to compare a synchronization of time of ovulation protocol for fixed-timed embryo transfer (FTET) with the usual administration of a single dose of prostaglandin associated with detection of estrus. Also, the effect of the presence of CL at the beginning of FTET protocol was evaluated. Lactating Holstein cows (n=651) with three previous artificial inseminations were classified according to presence or absence of a corpus luteum (CL). Cows with a CL were randomly assigned to two additional treatments and submitted to embryo transfer after detection of estrus (PGF-Estrus) or FTET (FTET-CL). Cows without CL were allocated to the FTET-NoCL treatment. On a random day of the estrous cycle (Day 0), cows in the PGF-Estrus treatment (n=229) were treated with 150 microg d-cloprostenol (PGF) i.m. followed by detection of estrus from Day 1 through Day 5 after PGF. Embryos were transferred 6-8 days after estrus detection. Cows in the FTET-CL (n=208; presence of CL) and FTET-NoCL (n=214; absence of CL) treatments received a norgestomet ear implant plus 2mg estradiol benzoate (EB) and 50mg progesterone i.m. on Day 0. On Day 8, the implant was removed and 400 IUeCG, 150 microg d-cloprostenol and 1mg estradiol cypionate i.m. were administered. No detection of estrus was performed and Day 10 was arbitrarily considered as the estrus day. Ultrasonographic exams were performed in all recipients and only cows with a single CL> or =15 mm or multiple CL received a fresh or frozen-thawed embryo on Day 17. Pregnancy was diagnosed by ultrasonography at 30 and 60 days of pregnancy. When FTET and PGF-Estrus were compared, the proportion of cows receiving an embryo (recipients transferred-to-treated rate) was greater in the FTET-CL (75.0% (156/208) than in PGF-Estrus (34.5%, 79/229; P<0.0001) treatment. Pregnancy rate (60 days) was also greater in FTET-CL (29.3%, 61/208) when compared to PGF-Estrus (16.2%, 37/229; P=0.001). However, no differences were found in pregnancy loss [PGF-Estrus=11.9% (5/42), FTET-CL=9.0% (6/67); P=0.62] and circulating progesterone concentration at embryo transfer [PGF-Estrus=4.02+/-0.52 ng/mL (n=25), FTET-CL=3.33+/-0.32 ng/mL (n=27); P=0.25] among these treatments. The presence of CL at the beginning of FTET protocol resulted greater transferred-to-treated rate [FTET-CL=75.0% (156/208) vs. FTET-NoCL=61.2% (131/214); P=0.003], but showed no effect on pregnancy rate at 60 days [FTET-CL=29.3% (61/208) vs. FTET-NoCL=22.9% (49/214); P=0.13], pregnancy loss [FTET-CL=9.0% (6/67) vs. FTET-NoCL=2.0% (1/50); P=0.15] and circulating progesterone concentration at ET [FTET-CL=3.33+/-0.32 ng/mL (n=27) compared to FTET-NoCL=3.44+/-0.40 ng/mL (n=2 9); P=0.82]. In conclusion, the protocol for synchronization of time of ovulation using norgestomet ear implant, EB and eCG increased recipients transferred-to-treated and pregnancy rates in high-producing repeat-breeder Holstein cows. Also, recipients without CL at the beginning of the time of ovulation synchronization treatment resulted in similar pregnancy rate as recipients with CL submitted to FTET protocol. Thus, the suggested protocol allowed the performance of FTET, without the need for detection of estrus, simplifying the reproductive management and increasing the reproductive efficiency in repeat-breeder Holstein recipients.

Angiogenesis and growth factor modulation induced by alternagin C, a snake venom disintegrin-like, cysteine-rich protein on a rat skin wound model.

In this work, we show that alternagin-C (ALT-C) and ALT-C PEP, a peptide derived from its sequence, were able to induce angiogenesis in wounded rat skin. A spherical cutaneous excision was made in the back of each animal and treated with three different concentrations of ALT-C or ALT-C PEP. After that, the skin was removed and analyzed to verify the presence of new vessels and the expression of growth factors. ALT-C and ALT-C PEP induced the formation of new vessels and modulated the expression of growth factors, mainly VEGF and FGF1. The expression of VEGF increased and it could be detected up to 7 days after injury. FGF1 also significantly increased, but at a lesser extent than VEGF. In conclusion, the present study shows for the first time the stimulation of angiogenesis in an injured tissue by a disintegrin-like protein and that ALT-C may exert this effect by modulating the expression of growth factors.

Effect of early luteolysis in progesterone-based timed AI protocols in Bos indicus, Bos indicus x Bos taurus, and Bos taurus heifers.

The objective of this study was to evaluate the effects of treatment with an intravaginal progesterone-releasing device (CIDR) and estradiol benzoate (EB) on follicular dynamics in Bos indicus (n=23), Bos taurus (n=25), and cross-bred (n=23) heifers. To assess the influence of reduced serum progesterone concentrations during 8 days of treatment with a progesterone-releasing device on follicular dynamics, half of the heifers received PGF at CIDR insertion (Day 0; 3 x 2 factorial design). Mean (+/-S.E.M.) serum progesterone concentrations during CIDR treatment varied (P<0.05) among genetic groups: B. indicus (5.4+/-0.1 ng/mL), B. taurus (3.3+/-0.0 ng/mL), and cross-bred (4.3+/-0.1 ng/mL). Maximum diameter of the dominant follicle (DF) was smaller (P<0.01) in B. indicus heifers (9.5+/-0.5 mm) than in cross-bred (12.3+/-0.4 mm) or B. taurus heifers (11.6+/-0.5 mm). B. indicus experienced lower (P<0.01) ovulation rate (39.1%) than did B. taurus (72.7%) and cross-bred (84.0%). Heifers treated with PGF on Day 0 had lower (P<0.05) serum progesterone concentrations during progesterone treatment. The PGF treatment on Day 0 increased (P<0.01) the diameter of the DF (11.9+/-0.4 mm vs. 10.5+/-0.4 mm). Moreover, greater (P=0.02) ovulation rates (78.8 vs. 54.0%) occurred in heifers treated with PGF on Day 0. In summary, B. indicus heifers had greater serum progesterone concentrations, smaller DF diameter, and a lower ovulation rate compared to B. taurus heifers. Prostaglandin treatment on the day of CIDR insertion reduced serum progesterone during treatment, and resulted in increased maximum DF diameter and ovulation rate.

Controle da síntese de prostaglandina F2 ALFA no endométrio bovino in vitro / In vitro control of prostaglandin F2a synthesis in bovine endometrium

A síntese de prostaglandina F2alfa(PGF2 alfa) endometrial, resulta de uma complexa cascata de eventos intracelulares que ocorrem de maneiraaltamente coordenada. A síntese de PGF2 alfa pode ser estimulada napresença da melitina e do forbol 12,13 dibutirato (PDBu). O objetivo do presente estudo foi verificar se a produção basal e a estimulação aguda de PGF2 alfa são dependentes da síntese de proteínas. No experimento 1, explantes obtidos de fêmeas bovinas (n=2), cíclicas, não lactantes, no dia 15 do ciclo estral foram incubados em quadruplicata, com meio de cultivo (KHB) ou KHB suplementado com PDBu 10(elevado a -6)M, melitina 10(elevado a -6)M ou melitina 10(elevado a-5)M. Amostras do meio foram coletadas 0 e 60 minutos após os tratamentos e as concentrações de PGF2 alfa foram mensuradas por radioimunoensaio. Com 60 minutos após os tratamentos houve aumento das concentrações médias de PGF2 alfa(P<0,06) em resposta ao tratamento com PDBu comparado ao grupo KHB e melitina. No experimento2, explantes endometriais de fêmeas bovinas (n=4), não gestantes,no 17° dia do ciclo estral, pesando de 80 a 100mg foram incubados em KHB suplementado com 0, 50, 100 ou 200mg/mL de CHX e 0 ou 100ng/mL de PDBu em um arranjo fatorial 2 x 4, em quadruplicata. Amostras do meio foram coletadas 0 e 60 minutos após os tratamentos e as concentrações de PGF2 alfa foram mensuradas por radioimunoensaio. A integridade dos explantes endometriais tratados com CHX foi avaliada por cortes histológicos. Foi observado aumento na produção de PGF2 alfa em resposta ao tratamento com PDBu(P<0,01), entretanto, não houve diferenças na produção de PGF2 alfa pelos tecidos tratados com diferentes concentrações de CHX, associadas ou não ao PDBu. A integridade histológica dos explantes foi preservada. Conclui-se que a produção basal e a estimulação aguda da síntese de PGF2 alfa não são dependentes da síntese de novas proteínas.

Synthesis of endometrial prostaglandin F2 a (PGF2 a) results from acomplex cascade of highly coordinated intracellular events. Production of PGF2 a can be stimulated by mellitin and 12, 13 phorbol dibutyrate(PDBu). Objective of the present study was to verify whether basal or stimulated synthesis of PGF2 a was dependent on de novo protein synthesis. In Experiment 1, endometrial explants from cyclic, non-lactating cross-bred beef cows (n=2) on day 15 of the estrous cycle were incubated in quadruplicate in culture KHB culture medium or medium supplemented with 10(involution-6)M PDBu, 10(involution-6)M melittin or 10(involution-5)M melittin. Medium samples were collected immediately and 60 minutes after treatment administration and concentration of PGF2 a in medium were measured by radioimmunoassay. Concentrations of PGF2a in medium were higher (P<0.06) after treatment with PDBu in comparison with control and melittin. In Experiment 2, endometrial explants from cyclic, non-lactating cross-bred beef cows (n=4) on day17 of the estrous cycle were incubated in quadruplicate in medium supplemented with 0, 50, 100 or 200mg cyclohexamide (CHX) and 0or 100ng/ml PDBu, in a 4 x 2 factorial arrangement. Medium sampleswere collected immediately and 60 minutes after administration of treatments and concentrations of PGF2 a measured by radioimmunoassay. Endometrial integrity was was evaluated by histology. Treatment with PDBu stimulated production of PGF2 a(P<0.01), regardless of concentration of CHX used. The CHX did not affect production of PGF2 a, either in the presence or absence of PDBu. Histological integrity of explants was preserved. It was concluded that both basal and PDBu-stimulated PGF2 a productionare not dependent on new protein sythesis.

Controle da síntese de prostaglandina F2 ALFA no endométrio bovino in vitro / In vitro control of prostaglandin F2a synthesis in bovine endometrium

A síntese de prostaglandina F2± (PGF2±) endometrial, resulta de uma complexa cascata de eventos intracelulares que ocorrem de maneira altamente coordenada. A síntese de PGF2± pode ser estimulada na presença da melitina e do forbol 12,13 dibutirato (PDBu). O objetivo do presente estudo foi verificar se a produção basal e a estimulação aguda de PGF2± são dependentes da síntese de proteínas. No experimento 1, explantes obtidos de fêmeas bovinas (n=2), cíclicas, não lactantes, no dia 15 do ciclo estral foram incubados em quadruplicata, com meio de cultivo (KHB) ou KHB suplementado com PDBu 10-6M, melitina 10-6M ou melitina 10-5M. Amostras do meio foram coletadas 0 e 60 minutos após os tratamentos e as concentrações de PGF2± foram mensuradas por radioimunoensaio. Com 60 minutos após os tratamentos houve aumento das concentrações médias de PGF2± (P<0,06) em resposta ao tratamento com PDBu comparado ao grupo KHB e melitina. No experimento 2, explantes endometriais de fêmeas bovinas (n=4), não gestantes, no 17° dia do ciclo estral, pesando de 80 a 100mg foram incubados em KHB suplementado com 0, 50, 100 ou 200mg/mL de CHX e 0 ou 100ng/mL de PDBu em um arranjo fatorial 2 x 4, em quadruplicata. Amostras do meio foram coletadas 0 e 60 minutos após os tratamentos e as concentrações de PGF2± foram mensuradas por radioimunoensaio. A integridade dos explantes endometriais tratados com CHX foi avaliada por cortes histológicos. Foi observado aumento na produção de PGF2± em resposta ao tratamento com PDBu (P<0,01), entretanto, não houve diferenças na produção de PGF2± pelos tecidos tratados com diferentes concentrações de CHX, associadas ou não ao PDBu. A integridade histológica dos explantes foi preservada. Conclui-se que a produção basal e a estimulação aguda da síntese de PGF2± não são dependentes da síntese de novas proteínas. (AU)

Synthesis of endometrial prostaglandin F2a (PGF2a) results from acomplex cascade of highly coordinated intracellular events. Productionof PGF2a can be stimulated by mellitin and 12, 13 phorbol dibutyrate(PDBu). Objective of the present study was to verify whether basalor stimulated synthesis of PGF2a was dependent on de novo proteinsynthesis. In Experiment 1, endometrial explants from cyclic, nonlactating cross-bred beef cows (n=2) on day 15 of the estrous cyclewere incubated in quadruplicate in culture KHB culture medium ormedium supplemented with 10-6M PDBu, 10-6M melittin or 10-5Mmelittin. Medium samples were collected immediately and 60 minutesafter treatment administration and concentration of PGF2a in mediumwere measured by radioimmunoassay. Concentrations of PGF2a inmedium were higher (P<0.06) after treatment with PDBu incomparison with control and melittin. In Experiment 2, endometrialexplants from cyclic, non-lactating cross-bred beef cows (n=4) on day17 of the estrous cycle were incubated in quadruplicate in mediumsupplemented with 0, 50, 100 or 200mg cyclohexamide (CHX) and 0or 100ng/ml PDBu, in a 4 x 2 factorial arrangement. Medium sampleswere collected immediately and 60 minutes after administration oftreatments and concentrations of PGF2a measured byradioimmunoassay. Endometrial integrity was was evaluated byhistology. Treatment with PDBu stimulated production of PGF2a(P<0.01), regardless of concentration of CHX used. The CHX didnot affect production of PGF2a, either in the presence or absence ofPDBu. Histological integrity of explants was preserved. It wasconcluded that both basal and PDBu-stimulated PGF2a productionare not dependent on new protein sythesis. (AU)

Influence of infection on patent ductus arteriosus and chronic lung disease in premature infants weighing 1000 grams or less.

OBJECTIVES: To test the hypotheses that (1) infection increases ductal dilatory prostaglandins and inflammatory mediators that may influence the closure of a patent ductus arteriosus (PDA), increasing the incidence of late episodes of PDA (after 7 days) and the rate of closure failures, and (2) the concurrence of PDA and infection increases the risk of chronic lung disease (CLD). METHODS: One hundred fourteen premature infants (birth weight, 500 to 1000 gm) were prospectively assessed for PDA and infection. Serum levels of 6-ketoprostaglandin F1 alpha and tumor necrosis factor alpha were measured routinely in all infants and when PDA or infection was present. Multivariate assessment of risk factors for PDA closure failure and for CLD was done by logistic regression, and expressed as an odds ratio and as 95% confidence intervals. RESULTS: Late PDA episodes were more frequent in infants with infection than in those without infection. A temporally related infection (<5 days between both diagnoses) was associated with an increased risk of PDA closure failure (odds ratio, 19.1 (confidence interval, 4 to 90)). In addition to birth weight and the severity of initial respiratory failure, PDA and infection increased the risk of CLD (odds ratio, 11.7 (confidence interval, 1.7 to 81) for PDA; odds ration, 3.1 (confidence interval, 1 to 11) for infection). Furthermore, when both factors were temporally related, they further increased the risk of CLD (odds ratio, 29.6 (confidence interval, 4.5 to >100)). Infants with infection and those with PDA had higher levels of 6-ketoprostaglandin F1 alpha than did control subjects. Levels of tumor necrosis factor alpha were also elevated in infants with infection and in those with late PDA. CONCLUSIONS: Infection adversely influences PDA outcome by increasing the risk of late ductal reopening and PDA closure failures. Increased levels of prostaglandins and tumor necrosis factor alpha in infants with infection may explain the poor PDA outcome. The concurrence of PDA and infection potentiates their negative effects on the risk of CLD.

Influence of prostaglandins on glucose transport in isolated rat uterus.

Glucose transport by uterine strips from ovariectomized estrogenized rats was explored. Sugar transport was significantly different from saccharose values (non-specific diffusion) only after 60 min of incubation. The addition of cytochalasin B demonstrated that we are measuring a specific mechanism for glucose transport. Insulin-enhanced sugar transport only at 0.5 or 0.25 U/ml prostaglandin E1 (PGE1), PGE2 and PGF2 alpha (10(-7) M) significantly improved glucose transport, but indomethacin (10(-6) M) failed in modifying this parameter in either control nor insulin-treated tissues. We did not observe an additive or synergistic action between PGE2 (10(-7) M) and insulin (used at maximal or submaximal concentration).

Prostaglandin catabolism and ulcerative colitis: effect of sulphasalazine, 5-aminosalicylic acid and other drugs.

1. Evidence is presented for the occurrence of type 1 prostaglandin 15-hydroxydehydrogenase in human rectal mucosa. No evidence of the presence of type 2 enzyme was found. 2. A 15-keto-prostaglandin reductase, responsible for the breakdown of 13,14-dihydro-15-keto prostaglandins to 13,14-dihydro prostaglandins, was also present in human rectal mucosa. 3. Ulcerative colitis patients catabolized prostaglandins to the same extent as the control group. PGE1 was catabolized significantly better than PGF2 alpha. 4. 5-Aminosalicylic acid and sulphapyridine did not affect prostaglandin catabolism. Sulphasalazine, methylsulphasalazine, indomethacin, flurbiprofen, disodium cromoglycate, sodium salicylate and carbenoxolone sodium inhibited prostaglandin catabolism to the same extent in both groups. Salicylazosulphadimidine was a more potent inhibitor of PGE1 catabolism than of PGF2 alpha. 5. The increased prostaglandin synthesis reported for ulcerative colitis patients was not paralleled by increased catabolism, a fact possibly contributing to the accumulation of such compounds in the diseased state.

Prostaglandin catabolism and ulcerative colitis: effect of sulphasalazine, 5-aminosalicylic acid and other drugs

1. Evidence is presented for the occurrence of type 1 prostaglandin 15-hidroxydehydrogenase in human rectal mucosa. No evidence of the presence of type 2 dnzyme was found. 2. A 15-keto-prostaglandin reductase, responsible for the breakdown of 13, 14-dihydro 15-keto prostaglandins to 13, 14-dihydro prostaglandins, was also present in human rectal mucosa. 3. Ulcerative colitis patients catabolized prostaglandins to the same extent as the control group. PGE was catabolized significantly better than PGF2 alfa. 4. 5-Aminosalicylic acid and sulphapyridine did not affect prostaglandin catabolism. Sulphasalazine, methilsulphasalazine, indomethacin, flurbiprofen, disodium cromoglycate, sodium salicylate and carbenoxolone sodium inhibited prostaglandin catabolism to the same extent in both groups.Salicylazosulphadimidine was a more potent inhibitor of PGE1 catabolism than of PGF2alfa. 5. The increased prostaglandin synthesis reported for ulcerative colitis patients was not paralleled by increased catabolism, a fact possibly contributing to the accumulation of such compounds in the diseased state