Scanning and transmission electron microscopic study of the obiductal epithelium of female albino rat during follicular and luteal phases of the estrous cycle

This work was done on fifteen virgin adult female albino rats to study regional differences and cyclic changes of the oviduct epithelium during the follicular and luteat phases of estrous cycle. Specimens from the fimbriae, ampulla and isthmus of the oviducts were prepared and examined by scanning and transmission electron microscopy. Scanning electron microscopic examination revealed that during the follicular phase, the fimbrial and ampullary epithelium were heavily ciliated. The cilia were uniform in length with even distribution and they concealed to a great extent the secretary. However, during the luteal phase the secretary cells were predominant with characteristic microvilli and solitary cilia protruding from their surfaces. The isthmic epithelium showed few changes between the follicular and the luteal phases of the estrous cycle, where the ciliated cells were irregularly distributed at both phases. However, the secretary cells appeared more prominent during the luteal phase. Transmission electron microscopic examination showed that the secretary cells of the fimbriae were columnar with ovoid nuclei and numerous long free border microvilli; the ampullary secretary cells were broad with few irregular microvilli. However, the isthmic secretary cells were broad with short blunt microvilli. Solitary cilia were found among the microvilli of the fimbrial and ampullary secretary cells. Two types of secretary granules were observed in the oviduct secretary cells, electron dense and electron lucent. During the follicular phase the secretary granules were almost of the electron dense type. However during the luteal phase, they increased and exhibited an electron - lucent appearance with centrally or peripherally located electron dense dots or patches. It is obvious from this study that the findings obtained be SEM were in accordance with and confirmed what found by the TEM. Both revealed marked regional differences and cyclic changes in the oviduct epithelium which might be necessary to meet varied requirements of the developing ovum. So, the tubal cells have to adjust themselves structurally and biochemically for such purpose

Protective effect of some dihydropyridine calcium channel blockers against cyclosporine induced nephrotoxicity in rats

The aim of the present study was to evaluate the protective effect of two dihydropyridine calcium channel blockers [CCBs], nifedipine [a well known calcium channel blocker] and lacidipine [a new calcium channel blocker with an antioxidant effect] against cyclosporine [CsA] induced nephrotoxicity in rats. The study included thirty adult male albino rats divided into five groups six rats each-Control gp Ia, were given distilled water; control gp lb. were given olive oil [vehicle of cyclosporine]. gp II rats, were given cyclosporine in a daily oral dose of 100 mg/kg, b.wt for 14 days; gp III and gp IV rats, were given nifedipine [NiF] and lacidipine [Lac] respectively in a daily oral dose of I mg I kg.bwt 3 days before and 14 days concurrently with cyclosporine-All animals were given ordinary laboratory food and tap water ad-libitum. and sacrificed after the last dose of drug administration. Blood samples were taken for estimation of serum creatinine and serum urea and kidney specimens were dissected immediately and processed for histological examination by light and transmission electron microscopy. Serum creatinine and urea levels were increased in CsA treated group [gp II] when compared to control group and were lower among groups received CCBs and CsA combinations [gp III and gp IV] in comparison with CsA treated group especially in gp IV given CsA and lacidipine combination. Light microscopic examination of kidney specimens of gp II rats given CsA only, showed focal necrosis and mononuclear cell infiltration of the renal cortex, vacuolation and detachement of the proximal tubules lining epithelium and congestion of the pen-tubular capillaries. These changes were much less pronounced in group III given CsA-nifedipine combination, while there was no changes in the renal cortex of gp IV rats given CsA-lacidipine combination. On the other hand electron microscopic examination of kidney specimens of gp II rats showed that the majority of the proximal tubules lining cells contain outstanding number of vacuoles, altered and degenerated mitochondria. giant mitochordria. large secondary lysosomes with heterogenous contents and thin and detached brush borden. Some of the distal tubules lining cells showed also vacuolated cytoplasm. occasionally giant mitothondna and increased lysosomes and some of the podocytes of the renal malpighian carpuscles showed vacuolated cytoplasm. distorted heterochromatinic nucleus and distorted foot processes. Kidney specimens of gp III and gp IV rats showed a lesser degree of ultrastructural alterations comparing with gp II rats. Proximal tubular cells of gp III rats given CsA-nifedipine combination showed a minimal degree of cytoplasmic vacuolations and few secondary lysosomes and no mictochondrial alterations-Proximal tubular cells of gp IV rats given CsA-lacidipine combination revealed nearly normal ultrastructure except of few primary Iysosomes-On the other hand both gps III and IV revealed no changes in the distal tubules or the renal malpighian corpuscles-From the previous findings, it was concluded that calcium channel blockers offered variable degree of protection against cyclosporine-induced nephrotoxicity in rats and that lacidipine has a better nephroprotective effect owing to its antioxidant effect besides its vasodilatory effect