الفهرس 
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Abstract
The present study is an endeavor to explore the relationship between induced hormonal alterations and ovarian activity in female Albino rats. For this purpose,Fifty mature cycling female Albino rats (160 – 180g B.W. ) were used, left for two weeks for acclimatization to the laboratory environment, kept under constant environmental and hygienic conditions as well as offered balanceddiet and water ad libitum. Animals were daily examined, in the morning, through application of vaginal smears to determine a regularity index of the estrous cycle and those showing 2 successive regular cycles were included in the current study. Subsequently, rats were equally divided randomlyinto 5 comparable groups; control, hyperglycemic, hypoglycemic, hypercorticosteroid and hypocorticosteroid groups. Moreover, vaginal smears examination continued in all groups along the experimental period ( 3 successive cycles ) The estrous day “ O day “ was considered the zeroday of the experiment forall groups. Samples were collected also on thepresumed estrous day following the experimental period to avoid the effect of estrous cyclephases on the estimated parameters. Moreover, animals were fasted for 2 hours before collection of blood samples.
Induction of hyperglycemia was done by a single intraperitoneal injection of purified alloxan( 150 mg / kg B.W. ) solubilized in 1.0 ml isotonic saline ( 0.85 % ) and prepared freshly just before injection while hypoglycemia ( hyperinsulinemia ) was induced using repeated daily S/C doses of 1.0 u. insulin/ 100 g B.W contained in 0.5 ml saline. After alloxan or insulin administration, rats with serum glucose levels of ≥180 or ≤ 90 mg/dl, respectively were included in the present study.Induction of hypercorticism was implemented by daily I/M injection of a corticosteroid ( dexamethasone sodium phosphate ) at a dose rate of 2.0 mg / rat contained in 0.5 ml saline daily for 12 successive days. On the other hand, induction of hypocorticism was carried out after surgical unilateral adrenalectomy.
At the end of the experimental period, individual blood samples were collected,under mild ether anesthesia, from the retro-orbital venous plexus at the medial canthus of the eye into dry sterile labeled tubes. Blood was left at room temperature for 2 hours then centrifuged at 3000 rpm for 15 minutes to obtain sera that were preserved at -20°C for determination of biochemical parameters. Moreover, tissue specimens,representing all groups, including the ovaries ( following calculation of gonadosomatic index ”GSI” ) andthe middle third part of the Fallopian tube ( 0.5 cm ), were taken out and preserved separately in 10 % formalin for histopathological examination. The collected sera were subjected to estimation of glucose, MDA, estradiol and progesterone levels.
The results showed that all hormonal treatments significantly induced alterations in the rhythmicity and phasic cellular characteristics of estrous cycle of female rats.The body weight ( g ), ovarian weight ( mg ) or GSI ( mg / 100 g body weight ) of mature Albino rats after different hormonal alterations for 3 successive cycles did not show any remarkable variation. Regarding circulating glucose level, it appeared that either alloxan or insulin treatments affected significantly ( P≤ 0.005 ) serum glucose level in cyclic female Albino rats as compared with that value of the controls. On the other side, hypercorticism led to marked elevation of serum glucose level while hypocorticism showed no significant effect on glucose level as compared with the corresponding control level. Serum malondialdehyde showed significant elevation only in hyperglycemic and hypocorticoid groups as compared with the corresponding value of the control group. Upon sex steroids level, hypoglycemia led to a significant decrease in serum estradiol while other treatments had no effect on this hormone. Upon progesterone, hypoglycemia resulted in an increased level of the hormone while other treatments led to reduced concentrations of the hormone in the circulation.
It was evident from estimation of sex steroids level as well as the histopathological findings of the ovaries and Fallopian tubes that abnormalities of the adrenal gland corticosteroids and / or pancreatic insulin levels are concomitant with irregular estrous cycle as well as ovarian and Fallopian tube structural alterations which resulted in deviated gonadal folliculogenesis and steroidogenesis( both E2 and P4 )and inhibited optimal reproductive performance in animals.
Therefore, upon reproductive purposes in animals,it is important to pay consideration to treat deviations of adrenal cortical hormones as well as pancreatic hormones to attain optimal reproductive performance.