Quantitative evaluation of pulomnary neuroendocrine cells and the role of nitric oxide in experimentally induced renovascular hypertension in male albino rats

Renovascular hypertension is the most common cause of secondary hypertension that leads to disorders in many systems and organs including the lung. The present work was carried out to determine how experimentally induced renovascular hypertension affects rat lung tissue with a special focus on the disorders in nitric oxide [NO] production as well as the number of pulmonary neuroendocrine cells. Twenty-one adult male albino rats were used; they were divided into three groups. Group I included five control rats, group II included eight rats that were sham operated, and group III included eight rats that were subjected to a renovascular hypertension procedure. Lower segments of the right lung lobes were obtained and then subjected to H and E and Masson's trichrome stains. Endothelial nitric oxide synthase [eNOS] and calcitonin antibody-2 were also used as immunohistochemical stains. Morphometric measurements included the area% of collagen fibers, the optical density of eNOS immunoreaction, and the number of calcitonin-positive neuroendocrine cells. Data were recorded and analyzed statistically. In group III, H and E-stained sections showed thickening of the tunica media of pulmonary arteries and alveolar walls with predominantly type II pneumocytes. Consequently, the thickened arteries showed a significant increase in the mean area% of collagen fibers, together with a significant decrease in the mean optical density of eNOS immunoreactivity when compared with the control group. The mean number of calcitonin immunoreactive neuroendocrine cells of group III showed a significant increase versus the control group. The current study showed an increased number of pulmonary neuroendocrine cells with renovascular hypertension. This increase may represent a compensatory mechanism to overcome renovascular hypertension. Thus, clinical trials could be conducted to prove the possible role of calcitonin-producing pulmonary neuroendocrine cells in controlling renovascular hypertension

Histological and immunohistochemical study of the effect of experimentally induced hypothyroidism on the thyroid gland and bone of male albino rats

Hyperstimulation of follicular cells using a goitrogen [propylthiouracil [PTU]] caused thyroid dysfunctions that were associated with disturbances in adult bone turnover. This work was carried out to study the probable relationship between follicular and parafollicular cells in drug-induced hypothyroidism caused by PTU and consequently its effect on bone. The present work was carried out on 30 adult male albino rats divided into three groups. Group I was the control group; group II [the hypothyroid group] rats received PTU orally at a daily dose of 16.875 mg/rat of an average weight of 180 g for 4 weeks; group III was the recovery group. Thyroid glands were examined using histological and immunohistochemical techniques for calcitonin Ab-2. The midshaft of the femur bones of the studied groups was prepared and stained with H and E. In hypothyroid rats both follicular and C cells displayed signs of hyperactivity as the mean follicular cell height was significantly increased [P<0.05] compared with the control group. Moreover, the calcitonin immunoreactive cells showed a significant increase [P<0.05] in the mean values of their height and mean area% and number compared with the control group. These findings were reflected on bone sections in terms of a significant increase [P<0.05] in cortical bone thickness and a significant narrowing [P<0.05] of the Haversian canals when compared with the control group. It could be concluded that C cells are not exclusively involved in calcium regulation independent of follicular cell activity; however, these cells interact with the surrounding follicular cells, enabling more effective coordinated functions between the two endocrine populations. Moreover, experimentally induced hypothyroidism resulted in increased C-cell number, consequently decreasing bone resorption and increasing cortical bone thickness

histological study on the effect of experimentally induced hyperthyroidism on adult albino rat testis

The thyroid hormone is a regulator of growth, development and metabolism in all tissues, and an altered thyroid status affects many organs. Studies correlating male sexual function with thyroid disorders are limited, probably because thyroid disorders are limited in men. The present work aimed to throw light on the effect of experimentally induced hyperthyroidism on the testes of adult albino rats with respect to testicular morphology, androgen receptor [AR], proliferating cell nuclear antigen [PCNA] and connexin43 [CX43] protein. Eighteen adult albino rats were used in this study and were divided into three groups of six rats each. Group I received 0.5 ml saline solution by intraperitoneal injection once daily for 4 weeks. Group II received an intraperitoneal injection of 40microg/kg L-thyroxin dissolved in saline solution daily for 4 weeks. Group III received thyroxin as in group II and were sacrificed 1 month after cessation of drug administration. Before scarification, serum thyroxin [T4] levels were determined. Sections were subjected to H and E and immunohistochemical staining for anti-AR, anti-PCNA and anti-connexin 43 antibodies. Morphometric studies included determination of the area% of immune reactions. In group II, the seminiferous tubules were lined by scanty apoptotic cells. There was homogeneous material between the seminiferous tubules. There was a significant decrease in the mean area% of anti-androgen, anti-PCNA and anti-CX43 antibodies compared with the control group. In group III the seminiferous tubules were apparently normal in shape and contained sperm in their lumen, separated by interstitial tissue. Although the mean area% of anti-AR, anti-PCNA and anti-CX43 was still lower, only the anti-PCNA antibody showed significant difference when compared with the control group. The current study showed that hyperthyroidism induced pronounced morphological changes in the testis

Assessment of rat endometrial pinopodes in normal cycles and following HCG ovarian hyperstimulation with or without progesterone supplementation: scanning electron microscopic study

Pinopodes, mushroom-like projections, arise from the endometrial surface at or just before the time of implantation. They have been proposed as a method of identifying endometrial receptivity for transferred embryo in programs of IVF. The present work was planned to assess the expression of pinopodes in rat endometrium in normal cycles and following ovarian hyperstimulation with or without progesterone supplementation as a trial to estimate the optimal date for successful embryo transfer in IVF programs. Forty-five adult female albino rats were divided equally into three groups. In the control group, ovulation was induced by mechanical vagino-cervical stimulation. Group II was subjected to ovarian hyperstimulation using human chorionic gonadotrophin [HCG] 350 IU/kg injected intraperitoneally [two injections 48h apart and vagino-cervical stimulation was performed on the evening of administration of the second injection. Group III was treated in the same way as group II, followed by a daily subcutaneous injection of progesterone 35mg/kg. All rats were sacrificed 3, and 5 days after vagino-cervical stimulation. The middle third of the right uterine horn were processes for scanning electron microscope examination. The mean number of pinopodes was statistically analyzed. In control rats, pinopodes started to appear on day 4 and significantly increased in number on day 5. In the HCG-ovarian hyperstimulated group, there was an early appearance of pinopodes on day 3, which increased in number on day 4 and regressed on day 5. With progesterone supplementation, there was an obvious increase in the number of pinopodes especially on day 4. It could be concluded that ovarian hyperstimulation using HCG may cause early expression of pinopodes and premature formation of an implantation window. Also, progesterone supplementation could enhance endometrial receptivity. This should be taken into consideration in IVF programs to synchronize embryo and endometrial development, which could improve pregnancy rates