Immunohistochemical determination of effects of Withania Somnifera root extract on noise stress induced adenohypophysis in albino rats

To access the ameliorating role of Withania somnifera root extract on noise stress effected Adenohypophysis morphology in albino rats by immuno-histochemical method. Experimental and observational study. This study was carried out at Department of Anatomy, Basic Medical Sciences Institute, Jinnah Postgraduate Medical center Karachi from January 2008 to December 2011. 90 adult male albino rats were divided into 3 groups A, B, C each group was divided into 2 subgroups A1-A2, B1-B2 and C1-C2 [24 hrs and 30 days] obtaining15 animals each. Group A served as control, group B were exposed to 100dBA noise for 24 hrs and 6hrs/day for 30 days as experimental design and group C was protected with Withania somnifera root extract along with noise stress. The animals were sacrificed at the end of experimental period of each subgroup and blood samples were collected for hormonal assay of the plasma ACTH and plasma Corticosterone concentration. Pituitary gland was removed from each animal and prepared for microscopic examination by immunohistochemical method. Immunohistochemical study reveals that, the black brown pigments deposited more in group B2 animals and reduced in group C animals Adenohypophysis indicated by ACTH monoclonal antibody Clone-56. The ACTH level was highly significantly increased after 24hrs and 30 days. The Corticosterone level was highly significantly decreased after 24hrs and not as much decreased after 30 days. It was restored insignificantly in protected groups after 24hrs and 30 days. Withania somnifera root extract has preventive efficacy against noise stress, immunohistochemistry confirmed that, less extent of black brown pigment deposition was the amount of corticotropes

Hormonal and Histomorphologic Effects of Azadirachta indica leaf Extract on the Pars Anterior of Wistar Rats / Efectos Hormonales e Histomorfológicosdel Extracto de la Hoja de Azadirachta indica en la Pars Anterior de Ratas Wistar

Azadirachta indica is a tree whose medicinal value is unquantifiable. Any part of the tree can be used in the treatment of malarial infection. Reports have indicated its antifertility effects, and this necessitated this study on the effects of the methanol leaf extract on serum luteinizing (LH) and follicle stimulating hormones (FSH) levels and the histomorphology of the pars anterior of Wistar rats. Thirty adult male Wistar rats were equally divided into 3 groups of A, B and C. Group A was the control and the animals received distilled water orally, while groups B and C were treated with 200mg/kg and 400mg/kg respectively of the leaf extract by oral gavage for fourteen days. On day fifteen, the animals were sacrificed by chloroform anaesthesia. Blood was obtained from their hearts, while the skull was opened to assess the hypophysis. Hormonal assay showed that luteinizing (LH) and follicle stimulating (FSH) hormone levels in the serum were lower in groups B and C treated with 200mg/kg and 400mg/kg respectively of the leaf extract, while that of LH were significant (P<0.001). Histomorphologic sections of the pars anterior revealed reduced acidophil and basophil populations, with prominent degranulated chromophobes which were larger in the group treated with 400mg/kg of A. indica leaf extract. This group also presented hypertrophy of the basophils compared to the control. In conclusion, methanol leaf extract of A. indica decreases serum LH and FSH and caused histomorphologic changes in the pars anterior of adult male Wistar rats.

Azadirachta indica es un árbol cuyo valor medicinal es invaluable. Cualquier parte del árbol se puede utilizar en el tratamiento de la infección por malaria. Reportes han indicado su efecto antifertilidad, lo que requirió estudiar los efectos del extracto metanólico de la hoja sobre los niveles séricos de las hormonas luteinizante (LH) y folículo estimulante (FSH) y la histomorfología de la pars anterior de ratas Wistar. Treinta ratas Wistar adultas fueron divididas en tres grupos. El grupo A fue utilizado como control y los animales recibieron agua destilada por vía oral, mientras que los grupos B y C fueron tratados con 200 mg/kg y 400 mg/kg respectivamente, con extracto de hoja mediante una sonda nasogástrica durante catorce días. A los quince días, los animales fueron sacrificados por anestesia con cloroformo. Se obtuvo sangre desde sus corazones, mientras que el cráneo fue abierto para evaluar la hipófisis. Los ensayos hormonales mostraron que los niveles en suero de la LH y FSH se redujeron en los grupos B y C, tratados con 200 mg/kg y 400 mg/kg respectivamente, siendo la reducción de LH significativa (p<0,001). Secciones histomorfológicos de la pars anterior revelaron una reducción de las poblaciones acidófilas y basófilas, con prominentes cromófobos degranulados que fueron mayores en el grupo tratado con 400 mg/kg del extracto de A. indica. Este grupo también presentó hipertrofia de los basófilos en comparación con el control. En conclusión, el extracto alcohólico de la hoja de de A. indica disminuye el nivel sérico de LH y FSH y provoca cambios histomorfológicos en la pars anterior de ratas Wistar adultas.

Genistein affects the morphology of pituitary ACTH cells and decreases circulating levels of ACTH and corticosterone in middle-aged male rats

The soybean phytoestrogen, genistein, is increasingly consumed as an alternative therapeutic for age-related diseases, namely cardiovascular conditions, cancer and osteoporosis. However, despite the beneficial effects on health, concern has been raised that this isoflavone also acts as an endocrine-disrupting chemical. The aim of this study was to examine the effects of genistein on immunohistomorphometric features of pituitary adrenocorticotropic cells (ACTH) and blood concentrations of ACTH and corticosterone in orchidectomized middle-aged male rats. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and genistein-treated orchidectomized (Orx+G) groups. Genistein (30mg/kg/day) was administered subcutaneously for three weeks, while the control groups received the vehicle alone. ACTH cells were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure. Circulating concentrations of ACTH and corticosterone were measured by immunoassay. Orchidectomy reduced (p<0.05) the cell volume and the relative volume of ACTH cells in comparison to SO rats. Genistein treatment further decreased (p<0.05) these morphometric parameters and reduced (p<0.05) circulating ACTH and corticosterone concentrations by more than 20 percent in comparison to both Orx and SO rats. In conclusión, genistein modulated the immunohistomorphometric features of ACTH cells and decreased blood ACTH and corticosterone levels, which supports evidence that this isoflavone affects the hypothalamic-pituitary-adrenal axis and suppresses glucocorticoid hormone secretion.

[Effect of morphine on the number of adenohypophysis acidophil cells in male rat]

The influence of morphine on pituitary secretion through micrimu receptors has been nearly known. It is also reported that morphine has an effect on cell proliferation. In the present study we investigated the effect of morphine on the proliferation of acidophil cells of adenohypophysis in male rat. This study has been carried out on 14 adult male Wistar rats divided into two groups of morphine dependent and control. The animals in morphine-dependent group were addicted through consumption of morphine for 21 days. After controlling withdrawal syndrome signs, serum prolactin level was determined by Elisa method. In the next step after anesthetizing animals and performing cardiac perfusion, the hypophysis was removed and fixed at 10% formalin. After processing, staining was done by routine immuno-histochemistry method and the number of mammotropes and somatotropes in morphine-dependent and control groups were compared. Mean prolactin production in dependent group as compared with control group showed significant increase. There was a significant increase in the ratio of mammotropes to acidophil cells and a significant decrease in the ratio of somototrops to acidophil cells in morphine-dependent group compared to the control group [P<0.05]. Morphine dependency may lead to increase in the percentage of prolactin secreting cells and serum prolactin level and decrease of growth hormone secreting cells

Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary

In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 æM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 æM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 æM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 æM cyclopentyltheophylline, a specific A1 receptor antagonist (1 æM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 æM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 æM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 æM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 æM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism.

Possible involvement of A1 receptors in the inhibition of gonadotropin secretion induced by adenosine in rat hemipituitaries in vitro

We investigated the participation of A1 or A2 receptors in the gonadotrope and their role in the regulation of LH and FSH secretion in adult rat hemipituitary preparations, using adenosine analogues. A dose-dependent inhibition of LH and FSH secretion was observed after the administration of graded doses of the R-isomer of phenylisopropyladenosine (R-PIA; 1 nM, 10 nM, 100 nM, 1 µM and 10 µM). The effect of R-PIA (10 nM) was blocked by the addition of 8-cyclopentyltheophylline (CPT), a selective A1 adenosine receptor antagonist, at the dose of 1 µM. The addition of an A2 receptor-specific agonist, 5-N-methylcarboxamidoadenosine (MECA), at the doses of 1 nM to 1 µM had no significant effect on LH or FSH secretion, suggesting the absence of this receptor subtype in the gonadotrope. However, a sharp inhibition of the basal secretion of these gonadotropins was observed after the administration of 10 µM MECA. This effect mimicked the inhibition induced by R-PIA, supporting the hypothesis of the presence of A1 receptors in the gonadotrope. R-PIA (1 nM to 1 µM) also inhibited the secretion of LH and FSH induced by phospholipase C (0.5 IU/ml) in a dose-dependent manner. These results suggest the presence of A1 receptors and the absence of A2 receptors in the gonadotrope. It is possible that the inhibition of LH and FSH secretion resulting from the activation of A1 receptors may have occurred independently of the increase in membrane phosphoinositide synthesis

Effects of estradiol benzoate on 5'-iodothyronine deiodinase activities in female rat anterior pituitary gland, liver and thyroid gland

There is little information on the possible effects of estrogen on the activity of 5'-deiodinase (5'-ID), an enzyme responsible for the generation of T3, the biologically active thyroid hormone. In the present study, anterior pituitary sonicates or hepatic and thyroid microsomes from ovariectomized (OVX) rats treated or not with estradiol benzoate (EB, 0.7 or 14 mug/100 g body weight, sc, for 10 days) were assayed for type I 5'-ID (5'-ID-I) and type II 5'-ID (5'-ID-II, only in pituitary) activities. The 5'-ID activity was evaluated by the release of (125)I from deiodinated (125)I rT3, using specific assay conditions for type I or type II. Serum TSH and free T3 and free T4 were measured by radioimmunoassay. OVX alone induced a reduction in pituitary 5'-ID-I (control = 723.7 + 67.9 vs OVX = 413.9 + 26.9; P<0.05), while the EB-treated OVX group showed activity similar to that of the normal group. Thyroid 5'-ID-I showed the same pattern of changes, but these changes were not statistically significant. Pituitary and hepatic 5'-ID-II did not show major alterations. The treatment with the higher EB dose (14 mug), contrary to the results obtained with the lower dose, had no effect on the reduced pituitary 5'-ID-I of OVX rats. However, it induced an imporatnt increment of 5'-ID-I in the thyroid gland (0.8 times higher than that of the normal group: control = 131.9 + 23.7 vs OVX + EB 14 mug = 248.0 + 31.2; P<0.05), which is associated with increased serum TSH (0.6-fold vs OVX, P<0.05) but normal serum free T3 and free T4. The data suggest that estrogen is a physiological stimulator of anterior pituitary 5'-ID-I and a potent stimulator of the thyroid enzyme when employed at high doses.

Effect of adenylate cyclase inhibitor and protein kinase C inhibitor on GnRH-induced LH release and LH beta subunit biosynthesis in rat anterior pituitary cells

According to our previous studies together with others, GnRH, a hypothalamic decapeptide, has been known to be a major regulator for LH release and its subunit biosynthesis in anterior pituitary gonadotropes. But the precise mechanisms by which GnRH exerts stimulatory effects on LH release and its subunit biosynthesis have not been clearly understood. In the present study we examined the effect of GnRH on protein kinase C (PKC) activity and intracellular cAMP content in cultured anterior pituitary cells of rat to clarify whether PKC or cAMP are involved in GnRH action. Moreover, we examined the effects of staurosporine (ST), a PKC inhibitor and 2',3'-dideoxyadenosine (2',3'-DDA), an adenylate cyclase inhibitor, on LH release and steady state LH beta subunit mRNA levels in cultured anterior pituitary cells of rat. PKC activity was rapidly increased within 30 min after GnRH treatment whereas intracellular cAMP level was elevated 18 h after GnRH treatment. ST significantly inhibited GnRH-induced LH release and LH beta subunit mRNA levels in a dose-dependent manner, showing an half maximal response at 50 nM ST. 2',3'-DDA inhibited GnRH-induced LH release and LH beta subunit mRNA levels in a dose-dependent manner in pituitary cells. From these results, it is suggested that GnRH stimulates LH beta subunit mRNA level as well as LH release in anterior pituitary cells and this GnRH action might be mediated by PKC activation and cAMP stimulation.

Effect of gossypol on pituitary reproductive axis: ultrastructural and biochemical studies.

Oral administration of gossypol induced sterility in male rats by 10 weeks, at a dose of 15 mg/kg body weight/day. The pituitary FSH gonadotroph cells showed dilated endoplasmic reticulum and accumulation of secretory granules in the cytoplasm. LH cells were degranulated. The Leydig cells showed enhanced synthetic activity. There was no change in testis weight and testicular RNA, lipids and cholesterol in the treated group while significant increase was observed in DNA content. Testicular sialic acid content decreased significantly over controls. The Sertoli cells, spermatogonia, spermatocytes and early spermatids were not affected after the treatment. The weights of prostate, seminal vesicle were recorded normal and there were no ultrastructural variations. The levels of acid and alkaline phosphatase and RNA in prostatic tissue were insignificant as compared with controls. However, DNA content of prostate gland showed a significant increase. Sialic acid of seminal vesicle + coagulating gland were within the control range. A marked reduction in fructose values from the same organ was noted.