Comparative LC-MS/MS-based molecular networking, DNA fingerprinting, and in vitro anti-Helicobacter pylori activity of three Egyptian Ficus cultivars.

Ficus species (Moraceae) have been used for nutrition and traditional medicine, and plants from this family are phytochemically abundant and serve as a potential source of natural products. As a result of the inherent complexity of the plant metabolomes and the fact that these Ficus species chemical space has not yet been fully decoded, it is still difficult to characterize their phytochemistry. Therefore, this study, we suggest the use of the molecular networking to elucidate the chemical classes existing in leaves of three Ficus species (F. deltoidei Jack, F. drupacea Thunb and F. sycomorus L.) and highlight the importance of molecular networking in examining their chemotaxonomy . By using computational tools, 90 metabolites were annotated , including phenolic acids, flavonoids, furanocoumarins, fatty acids and terpenoids. Phenolic acids were detected as the main class present in the three studied species. Flavonoids-C-glycosides, flavonoids-O-glycosides and isoflavonoids were mainly present in F. drupacea and F. sycomorus, while furanocoumarins were proposed in F. sycomorus. Vomifoliol-based sesquiterpenes were proposed in F. deltoidei. The chemotaxonomic differentiation agreed with the DNA fingerprinting using SCOT and ISSR markers. F. deltoidei, in particular, had a divergent chemical fingerprint as well as a different genotype. Chemotype differentiation using chemical fingerprints, in conjunction with the proposed genetic markers, creates an effective identification tool for the quality control of the raw materials and products derived from those three Ficus species. As well, F. drupacea exploited the most potent inhibition of H. pylori with MIC of 7.81 µg/ mL compared with clarithromycin. Overall, molecular networking provides a promising approach for the exploration of the chemical space of plant metabolomes and the elucidation of chemotaxonomy.

Selection criteria for resuscitation and survivability rates for neonates at the limit of viability.

AIM: To evaluate outcomes of a cohort of infants born at 23 weeks' gestational age after introducing a new selection score for resuscitation in the delivery room (DR). METHODS: This was a retrospective charts review study using data from the maternal and newborn registry funded by the Qatar National Research Fund. Parents were consulted prenatally and their wishes were honored. The plan of resuscitation was based on the new selection score. The seven components of the score were four antenatal and three immediate postnatal in the DR. Each component received a score of zero, one, or two according to its presence, uncertainty or absence, respectively. Only a score of≥7 would receive active resuscitation unless specified otherwise during prenatal consultation. RESULTS: The study reviewed 60 infants that were delivered over a two year period. The DR death rate was 23 of 60 (38%). Thirty-seven infants (61%) were admitted to the NICU. The score was applied only on 37 infants where all score criteria were reported in their files. Twenty infants had score <7; of them 13 (65%) died in the DR and 7 were admitted to NICU of whom two (29%) survived to discharge. Seventeen babies with scores≥7 admitted to NICU of whom nine (51%) survived to discharge. The survival rate to discharge was 13 of 37(35%). A satisfaction survey included 33 neonatal physicians; 32 neonatologists stated the score was easy to comprehend, 26 voted for easy to implement, and 30 voted for ethical relief and moral comfort. CONCLUSIONS: Using a resuscitation score of seven was associated with improved survival until the discharge of those infants resuscitated. NICU physicians described the score as functional and convenient.

Efficacy of intraperitoneal bupivacaine, hydrocortisone, and magnesium sulfate in different combinations for pain relief after laparoscopic ovarian cystectomy: a double-blind randomized controlled trial.

BACKGROUND: The aim of this study was to assess the efficacy of intraperitoneal different combinations for postoperative pain relief in patients undergoing laparoscopic unilateral ovarian cystectomy. METHODS: We conducted a double-blind randomized controlled trial that enrolled patients who were included to undergo laparoscopic unilateral ovarian cystectomy. Patients received one of the following combinations (30 patients each): group I: received bupivacaine plus magnesium sulfate, group II: received bupivacaine plus hydrocortisone, group III: received magnesium sulfate plus hydrocortisone, and group IV: received saline 0.9% only. The primary outcomes in the present study were the severity of postoperative abdominal and shoulder pain assessed by visual analog scale (VAS) every two hours till the end of the first day, and time for first postoperative analgesia requirement. RESULTS: Group I had statistically significant lower abdominal static and dynamic pain scores than the other groups till 18 hours postoperatively (P<0.001). In addition, group II had statistically significant lower abdominal static and dynamic pain scores than group III in the most of assessment points (P<0.05). The time for first required analgesics was significantly longer in group I (336.2±67.54 minutes) than other groups (P<0.001). The proportion of patients who required two or more doses of ketorolac was significantly lower in group I than other groups (P<0.001). The proportion of patients with nausea or vomiting was not significantly different across study's groups (P>0.05). CONCLUSIONS: Intraperitoneal bupivacaine-magnesium combination provides better analgesia and reduces postoperative morphine consumption than bupivacaine-hydrocortisone or magnesium-hydrocortisone combinations after laparoscopic ovarian cystectomy.

Phytochemical constituents and chemosystematic significance of Chrozophora tinctoria (L.) Raf.

Twelve compounds were isolated from Chrozophora tinctoria (L.) Raf. They were identified as kaempferol, kaempferol 3-O-ß-glucopyranoside, kaempferol 3-O-(6″-α-rhamnopyranosyl)-ß-glucopyranoside, quercetin, quercetin 3-O-ß-glucopyranoside, quercetin 3-O-(6″-α-rhamnopyranosyl)-ß-glucopyranoside, apigenin, apigenin 7-O-ß-glucopyranoside, acacetin, gallic acid, methyl gallate and ß-sitosterol-3-O-ß-glucopyranoside. Their structures were elucidated by chemical and spectral methods. Furthermore, chemosystematics of the isolated compounds is briefly discussed. It was indicated that C. tinctoria is the only species of Chrozophora that has the capability to synthesis kaempferol aglycone and their glycosides, and the finding is supported by its distinct morphological and anatomical aspects.

Oxytocin as a novel therapeutic option for type I diabetes and diabetic osteopathy.

OBJECTIVE: The aim of the present study was to highlight the newly discovered metabolic role of oxytocin (OT) in the type I diabetic rats. Previous studies have demonstrated that OT has a beneficial role on bone physiology and therefore, the OT effect on the diabetic osteopathy will be assessed as well. METHODS: Induction of the type I diabetes was carried out by an intraperitoneal injection of 60 mg/kg body weight of streptozotocin. The metabolic role of OT on diabetic rats after OT treatment with intramuscular injection of 40 µIU/kg body weight for 6 weeks was assessed. Histological and ultrastructural studies of rat pancreas samples, before and after the OT injection, were performed and compared with the obtained physiological results. RESULTS: Oxytocin treatment had positive metabolic effects in diabetic rats. This is based on the change in glucose metabolism, lipid profile, and insulin sensitivity in experimental animals. In addition, OT treatment showed histological regenerative changes of pancreatic islet cells of diabetic rats. Moreover, OT administration showed that it has an anabolic effect on the bone biology. CONCLUSIONS: The results suggest that activation of the oxytocin receptor (OTR) pathway by infusion of OT, OT analogs, or OT agonists may represent a promising approach for the treatment of diabetes and some of its complications, including diabetic osteopathy.

Study of the role of interleukin-6 and highly sensitive C-reactive protein in diabetic nephropathy in type 1 diabetic patients.

BACKGROUND: Diabetes Mellitus (DM) is becoming an increasingly common disease which is the leading cause of chronic renal failure. The pathogenesis of diabetic nephropathy is still a matter of debate. There are conflicting results regarding the relation of C reactive protein (CRP), interleukin-6 (IL-6) and diabetic nephropathy in type 1 diabetes. OBJECTIVES: This study was aiming to determine the association between higly sensitive (Hs)-CRP and IL6 with nephropathy in a sample of type 1 diabetic Egyptian patients. MATERIALS AND METHODS: The study was conducted on forty type-1 diabetic patients (Group I), who subdivided into three subgroups according to their urine albumin excretion rate (AER); Group IA: 10 patients with AER <20 microg/min, Group IB: 15 patients with AER ranges from 20-200 microg/min. Group IC: 15 patients with AER is > 200 microg/min and 10 healthy subjects as a control (Group II). RESULTS: There were high statistical significant difference (p < 0.001) between group I with group II regarding HsCRP (4.39 +/- 1.94, 1.32 +/- 0.39), and IL-6 (2.82 +/- 0.76, 1.95 +/- 0.35). In group I, we found a positive significant correlation (p < 0 .001) between UAE and levels of Hs-CRP (r = 0.927), and IL-6 (r = 0.838), respectively. Also, a positive significant correlation between Hs-CRP and IL-6 (r = 0.728, p < 0.001) was found. Fasting plasma glucose (FPG) level and HbA1c showed a significant positive correlation (p < 0.001) with Hs-CRP (r = 0.531) (r = 0.750), and IL-6 (r = 0. 490) (r = 0.680) respectively. CONCLUSION: Hs-CRP and IL-6 are sensitive markers for diabetic nephropathy predicting its progression and severity in type 1 diabetics.

Thyroid hormone patterns in elderly patients undergoing elective coronary procedures.

BACKGROUND AND OBJECTIVES: Thyroid dysfunction is common in the elderly. We sought to explore thyroid hormone patterns in a series of elderly patients undergoing elective coronary procedures and their relation to the extent of coronary artery disease. MATERIALS AND METHODS: We enrolled 81 consecutive elderly patients admitted to undergo elective diagnostic or interventional coronary procedures. Samples were collected for assay of free thyroxin, free tri-iodothyronine, thyroid stimulating hormone, anti-thyroglobulin and anti-thyroid peroxidase antibodies. According to the number of coronary arteries affected by significant stenosis (> or = 70% luminal obstruction), we classified patients into a group with insignificant coronary disease, another with single vessel disease, and a third group with multi-vessel disease. RESULTS: Forty one (50.6%) patients were euthyroid, two patients (2.5%) had subclinical hypothyroidism, and 12 (14.8%) had clinical hypothyroidism. Yet, neither subclinical nor clinical hypothyroidism was statistically different among the 3 groups, (p > 0.05 for both). Additionally, 3 patients (3.7%) had subclinical, and 2 (2.5%) had clinical hyperthyroidism. Finally, 21 patients (25.9%) had sick euthyroid syndrome. Again, all were statistically similar between the study groups, (p > 0.5 for all). Similarly, both anti-thyroglobulin antibodies and anti-thyroid peroxidase antibodies were statistically similar among the 3 groups (p > 0.05 for both). CONCLUSION: Thyroid hormone disturbances are quite frequent in elderly patients undergoing elective coronary procedures, chiefly in the form of a hypothyroid state. These data do not support that thyroid hormone patterns relate to the extent of coronary artery disease in the elderly.

Possible neuroendocrine role for oxytocin in bone remodeling.

OBJECTIVE: The present study was carried out to evaluate the assumption that oxytocin (OT) plays a neuroendocrine role in bone remodeling. For this purpose the changes in serum calcium, serum RANKL and OPG levels were detected in addition to morphological examination of the bone. METHODS: Two regimes for OT administration were used: 1. one group of rats was treated with a high OT dose of 40 microIU/kg b.w. for 6 weeks; 2. second group was treated with a low OT dose of 8 microIU/kg b.w. for a longer period of treatment (12 weeks). To evaluate the possible role of OT in bone remodeling, the changes in serum calcium, serum RANKL (sRANKL--Receptor Activator of Nuclear factor K-beta Ligand) and OPG (Osteoprotegerin) levels were detected and sRANKL/OPG ratio was calculated. To confirm the biochemical data, a histological and ultrastructural study of rat bone samples, before and after injection with oxytocin, was also performed. RESULTS: In general, the present study shows that intramuscular injection of OT at both concentrations and durations of treatment caused a significant decrease in serum calcium and sRANKL levels and a significant increase in OPG level. The sRANKL/OPG ratio was decreased as well. Morphological observations showed that both OT treatments induced a slight effect on bone remodeling in favor of bone formation. CONCLUSION: Oxytocin was found to posses a growth promoting effects on bone. The results also clearly showed that treatment with a high OT dose for a short duration was more effective than the low dose for a longer period of treatment.

The Harderian gland of the Dhub lizard Uromastyx microlepis of the Kuwaiti desert: an ultrastructural approach.

Harderian glands exist in the orbits of most terrestrial vertebrates. The basic function of the gland is the lubrication of the eye. The present study was carried out to shed some light on the ultrastructure of the still enigmatic Harderian gland of the lizard Uromastyx microlepis, a common species in Kuwait and other Gulf areas. The Harderian gland of Uromastyx microlepis is well developed, relatively large in size and lingual in shape. The epithelial cells of the anterior part of the gland are characterized by the presence of membrane bound granules of almost homogeneous consistency. These secretory granules are gathered in compartments and separated by membranes and stacks of granular endoplasmic reticulum (GER). Most of the lumina were empty. Moderate amounts of GER, free ribosomes and pleiomorphic mitochondria were observed in the perinuclear area of the epithelial cells. The medial and caudal parts of the gland were rich in special secretory granules, GER, free ribosomes and pleiomorphic mitochondria. The anterior part of the gland could represent the future lacrimal gland of mammals. A network of myoepithelial cells was recognized around the gland tubules. While no melanocytes or lymphocytes were observed in the scarce interstitial tissue, macrophages, that might have an immune function in the gland, were observed.

beta-glucuronidase activity is elevated in the rat harderian gland after bromocriptine but decreased after cyproterone acetate treatment or castration. Postcastrational effects on the ultrastructure of the gland.

OBJECTIVE: To investigate the effect of castration, bromocriptine and cyproterone acetate treatment on lysosomal hydrolytic enzymes and ultrastructure of the rat Harderian gland. METHODS: Groups of rats were subjected to the treatment by bromocriptine, cyproterone acetate and castration. Harderian glands were dissected from each experimental animal cut into small pieces and immediately stored in liquid nitrogen. Only those from castrated animals were fixed in Karnovsky fluid and processed for electron microscopy. The activity of acid phosphatase and ss-glucuronidase were estimated by kits from Sigma (St. Louis, Mo, USA). Semi-thin sections were stained with 1-% toluidine blue and ultra-thin sections with uranyl acetate and counter-stained with lead citrate. The examination was performed by Joel JEM-1200 EX II electron microscope. RESULTS: The treatment of male rats with the prolactin release inhibitor bromocriptine induced a significant increase in ss-glucuronidase activity. On the contrary, such activity was significantly decreased after treatment with the testosterone receptor antagonist cyproterone acetate as well as after castration. However, these treatments did not alter the activity of lysosomal acid phosphatase. Castration induced dramatic changes mostly in type A cells such as the appearance of lipid vacuoles with irregular forms and the predomination of smooth endoplasmic reticulum (SER) throughout the cytoplasm. The most dramatic postcastrational change was the degeneration of the mitochondria. These changes in type A cells might be due to the uneven distribution of the testosterone receptors in the rat Harderian gland, which are more numerous in type A cells. CONCLUSIONS: the gland physiology is responsive to alteration in circulating prolactin and testosterone levels.

The Harderian gland of the Cheesman's gerbil (Gerbillus cheesmani ) of the Kuwaiti desert.

The Harderian gland is a large orbital structure. Several functions have been ascribed to the gland such as lubrication of the eye, a source of pheromones, thermoregulartory lipids and photoprotective secretions and a part of the retinal-pineal axis. In the present study, the Harderian gland of the Cheesman's gerbil, Gerbillus cheesmani, is described for the first time. The gland is located around the posterior portion of the eyeball. The gland is compound tubular, surrounded by a thin connective tissue capsule. Only one secretory epithelial cell type was recognized, characterized by the presence of lipid vacuoles and cytoplasmic slashes in high numbers; the former being more concentrated towards the apical part while the latter being more concentrated towards the central and basal parts. Some of the cytoplasmic slashes contained electron dense filamentous structures. Similar structures were observed in the lipid vacuoles. Thus, a functional relationship between the cytoplasmic slashes and the lipid vacuoles is suggested. A unique structure was observed, termed dome-like cells, located between the epithelial cells and the basement membrane. These cells were characterized by the extensive presence of pleomorphic mitochondria and compact lamellae of granular endoplasmic reticulum (GER) in the form of finger prints. The gland was found to be actively secreting porphyrins as well as lipids. Cellular debris was also seen in the tubular lumina. Myoepithelial cells with their spindle shape and elongated nuclei were evident between the basement membrane and the secretory epithelium. Sparse interstitial tissue was observed in-between the gland tubules of both male and female gerbils. Macrophages, dendritic melanocytes and lymphocytes are the most represented cellular components of the interstitium. Further studies are required to investigate the function of the dome-like cells as well as the role of lymphocytes in the rodents Harderian gland.

Pineal gland of the Kuwaiti desert gerbil (Gerbillus cheesmani): alterations of its structure by bromocriptine treatment.

In the present study, the pineal gland of the gerbil Gerbillus cheesmani was described for the first time. According to their electron density, two distinct cell types were observed (light and dark pinealocytes). The nuclei were either oval or irregular. Moderate amount of granular endoplasmic reticulum (GER) was observed. Free ribosomes were present throughout the cytoplasm. Mitochondria and lysosomes were among the most common organelles in the pinealocytes. Several dense core vesicles (DCV) were also noted. Blood capillaries with nonfenestrated endothelium were frequent. Bromocriptine treatment for two weeks influenced, to a degree, the physiology of the pinealocytes. It induced a loss of distinction between light and dark pinealocytes, a decrease in the amount of GER and a reduced frequency of lysosomes. On the contrary, lipid droplets and membrane bound vesicles became more frequent.

CAFFEINE INJECTION IN THE DARK PHASE PROLONGS THE NOCTURNAL RISE IN SEROTONIN N-ACETYLTRANSFERASE ACTIVITY AND MELATONIN CONTENT IN THE PINEAL GLAND OF MALE RATS.

Caffeine, an important member of methylxanthines, induced a prolonged nocturnal rise in pineal melatonin content and an increase in its rate-limiting enzyme serotonin N-acetyltransferase (NAT) activity. The highest levels were reached five hours after subcutaneous caffeine injection to male rats in the dark phase, where the NAT activity increased from 920+/-70 pM/pineal/h in the control group to 1190+/-120 pM/pineal/h (P<0.001) in the treated group. The pineal melatonin content, as well, was elevated from 520+/-40 pg/pineal in the control group to 1120+/-80 pg/pineal (P<0.001) in caffeine treated group. These changes could be attributed to the depressive effect of caffeine on the activity of phosphodiesterase (PDE), the enzyme responsible for the hydrolysis of the intracellular second messenger cyclic adenosine monophosphate (cAMP).

Elevated serum cortisol and glucose and liver glycogen in juvenile fish Clarias lazera after exposure to acid stress.

The exposure of juvenile Clarias lazera to acute (pH 3.1 for 96 h) and chronic (pH 5.4 or 4.7 for 12 weeks) acid stress (H2SO4) resulted in a number of physiological responses which could be considered as adaptive to the effects of stress. These responses were evident in the rapid rise of serum cortisol level from 43.0 +/- 0.76 microgram/dl in the control to 71.0 +/- 1.06 micrograms/dl (P < 0.001) 24 h after acute exposure. Also serum glucose level was increased from 123.66 +/- 1.85 mg/dl in the control and reached 295.0 +/- 2.89 mg/dl (P < 0.001) by the end of the experimental period (96 h). Chronic exposure of the fish to the two levels of pH (5.4 and 4.7) caused significant increase in serum cortisol and serum glucose level starting from the first week of exposure and lasted throughout the study period (12 weeks). As to the liver glycogen content, a slight but significant drop was found from 11.06 +/- 0.03 mg/100 mg tissue dry weight in the control to 10.80 +/- 0.06 mg/100 mg tissue dry weight (P < 0.025) 24 h after acute acid exposure. However, the values at 72 and 96 h were significantly higher than those in the control. In the chronic exposure study, the fish maintained at pH 5.4 showed a marked increase in liver glycogen content starting from week 2 and lasted till the end of experimental period (12 weeks). As early as after one week of treatment, in fish maintained in pH 4.7, liver glycogen content surged and remained significantly high till the twelfth week.

Periventricular nucleus lesioning modulates specific somatostatin binding in various brain regions and anterior pituitary.

The effects of periventricular nucleus (Pe) lesioning on the plasma growth hormone (GH) levels and the anterior pituitary (A.P.) and brain somatostatin (SRIF) receptors were studied. A transient significant increase in plasma GH level in lesioned rats was detected 1 day after the operation. This elevated level of plasma GH started to decrease 3 days after lesioning. These changes were paralleled by an increase in binding of 125I-Tyr11-SRIF-14 to the A.P. 1 day after lesioning. This result could further confirm that the SRIF inhibitory action on GH release takes place at the A.P. level. Also, a transient increase in binding of the radioligand was detected in some brain areas 1 and 4 days after the lesion. However, the mechanism by which this increase takes place remains to be elucidated.

Immunoreactive somatostatin content in the pineal gland increases after lesion of the hypothalamic periventricular nucleus in male rats.

Immunoreactive somatostatin (IRS) content in the pineal gland increased about two-fold when the hypothalamic periventricular nucleus (Pe) of male rats, which contains many tuberoinfundibular somatostatin (SRIF) neuron cell bodies, was lesioned. However, the mechanism by which this increase takes place remains to be elucidated. Using 125I-Tyr11-SRIF-14 as a ligand and autoradiography, specific binding was detected in several brain areas. However, we were unable to detect specific SRIF binding sites either in the pineals of control or lesioned animals. This undetectable binding of SRIF-14 could be due to the localization of low-affinity receptors that were not demonstrated by the present method. Another possibility for the undetectable binding of the radioligand to the pineal could be due to the fact that the majority of IRS may be within the nerve terminals and the receptors in a different location.

Developmental, histological and ultrastructural studies on the harderian gland of the Egyptian toad, Bufo regularis Reuss.

The present study shows that the Harderian gland of the toad Bufo regularis starts to appear during development at stage 57 concomitant with the development of the nictitating membrane. In the adult toad, the gland was found to be formed of one lobe and occupying the antero-ventral aspect of the orbital cavity. No anatomical differences were noted between the male and female glands. The histological and ultrastructural studies showed that the Harderian gland is a compound tubular gland composed of rounded tubules lined by a single layer of epithelial cells and having a meshwork of myoepithelial cells surrounding the gland tubules. Differences were observed in the epithelial cells of female and male toads Bufo regularis. While females have a dilated rough endoplasmic reticulum and several secretory granules throughout the cytoplasm, males have a compact rough endoplasmic reticulum and numerous secretory granules and vacuoles.

Daily cycles of putrescine, spermidine, and spermine in the liver, pineal gland, harderian gland, anterior pituitary, and testes of rats kept in LD 12:12.

A circadian rhythm in cellular polyamine levels was detected in the liver, pineal gland, anterior pituitary gland, Harderian gland, and testicular seminiferous tubules of male rats fed ad libitum and maintained in a light:dark cycle of LD 12:12 (lights on at 07:00). Liver putrescine content was highest at 24:00, showing a sixfold increase over 12:00 levels. Pineal spermidine and spermine contents reached a maximum at 06:00, late in the dark phase. A similar pattern was also detected in the Harderian gland. In the anterior pituitary, the polyamines putrescine, spermidine and spermine were highest at 18:00, late in the light phase. However, the increase in putrescine was not statistically significant. The three polyamine contents decreased late in the dark phase. In testicular seminiferous tubules putrescine, on the contrary, was highest (about a twofold increase) late in the dark phase.

Rate of reproductive involution following either exposure to short days or daily administration of melatonin is faster in inbred than in random-bred female Syrian hamsters.

The onset of cessation of oestrous cyclicity and associated organ and hormonal changes were compared in random-bred (RB) and inbred (IB) female Syrian hamsters kept either under short days (8 h light:16 h darkness; 8L:16D) or long days (14L:10D) and given daily afternoon injections of 25 micrograms melatonin. In response to short-day treatment, 100% of the IB hamsters exhibited vaginal acyclicity within 35 days; by comparison, none of the RB animals were acyclic at this time. The IB hamsters also exhibited other changes associated with exposure to short days, including increased body weight, enlarged ovaries, regressed uteri, elevated pituitary concentrations of FSH, and depressed pituitary and plasma concentrations of prolactin. At this time, only the pituitary FSH levels were increased in the RB animals kept under the same short-day conditions. In a second experiment, RB and IB female Syrian hamsters were maintained under long days (14L:10D) and the rate of reproductive regression in response to daily afternoon injections of melatonin was compared. After 8 weeks of melatonin injections, 80% of the IB females were anoestrous, while all RB hamsters were still exhibiting 4-day oestrous cycles. Other changes associated with melatonin administration in the IB females included a marked drop in uterine weight and a depression in pituitary and plasma prolactin levels. The RB hamsters, although they were all still cyclic after 8 weeks, had increased body and ovarian weights, increased pituitary concentrations of FSH, and lower pituitary and plasma prolactin levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Undernutrition potentiates melatonin effects in maturing female rats.

Prepubertal (21-22 days) female Sprague-Dawley rats were caged singly in either long (LP; 14:10 LD) or short (SP; 8:16 LD) photoperiod and fed ad libitum or underfed (1/2 the food intake of controls). Additionally, a fed and underfed group in LP received a daily sc injection of saline or 100 micrograms melatonin at 1700 h. Food restriction delayed vaginal opening and resulted in a reduction in body weight and in the weights of the pituitary, ovary and uterus in all underfed groups. Melatonin treatment (but not SP exposure) significantly enhanced the reduction in pituitary, ovarian and uterine weight compared to the underfed saline-treated controls. Thyroid weights were significantly increased in underfed LP and SP groups compared to their respective controls where melatonin treatment in either fed or underfed animals was ineffective. Underfeeding caused a significant rise in pituitary LH (except for SP-underfed group) and FSH concentrations and a fall in pituitary prolactin concentrations and plasma T3 levels. Melatonin injections in underfed rats significantly increased pituitary LH and FSH and decreased prolactin concentrations compared to underfed saline-treated animals. Plasma prolactin levels increased after melatonin administration in both fed and underfed rats. These observations emphasize that environmental influences such as undernutrition can alter the physiological status of immature animals and enhance the sensitivity of the neuroendocrine axis to the pineal and one of its hormones, melatonin.