Estradiol Modulation of Pineal Gland Activity in the Wild Bandicoot Rat, &lt;i&gt;Bandicota bengalensis&lt;/i&gt;

2010

IJB

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Hormone-induced reponsiveness of the pineal and adrenal glands was studied in post-pubertal male mice (Mus musculus). The influence of steroid hormones (estradiol and testosterone) and non-steroidal antihormones (tamoxifen and flutamide) on pineal and adrenal karyomorphology and cell proliferation activity was analyzed. Estradiol was injected at a dose of 5µg, testosterone 100µg, tamoxifen 500µg and flutamide 2mg per 100g body weight administered intramuscularly in all cases for ten consecutive days. Control mice were similarly injected with 0.3ml of peanut oil vehicle intramuscularly for the same duration. The results indicated that, except testosterone, all other treatments with estradiol, tamoxifen and flutamide caused significant hyperactivity in both the pineal and the adrenal glands, associated with significantly increased cell proliferation activity. On the contrary, testosterone administration was inhibitory to pineal -adrenal karyometric and mitotic incidence values. It was concluded that in male post-pubertal mice both pineal and adrenal glands show antagonistic response towards estradiol and testosterone administration. Although tamoxifen showed estrogen agonistic behaviour, flutamide conversely induced pineal and adrenal cytophysiological stimulation. Such stimulatory response was antagonistic to the inhibitory response shown by pineal and adrenal karyomorphology and cell proliferation following testosterone administration.

Section: Discussionsupporting

confidence: 68%

“…This hormone however induced mitosis in pinealocytes of juvenile female rats (Sahu & Chakraborty 1986). Similarly earlier reports from bandicoot rats show pineal stimulation by estradiol .…”

Section: Introductionsupporting

confidence: 81%

Steroid hormone and antihormone induced changes in the pineal and adrenocortical karyomorphology and cell proliferation in mice ( Mus musculus )

Bandyopadhyay¹,

Dasgupta²,

2010

IJB

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“…It is interesting to note that the cytophysiological changes indicated by karyomorphological alterations in the pineal gland (Quay, 1965(Quay, , 1976Diehl et al, 1984;Sahu & Chakraborty, 1983, 1986Hira et al, 1989;Peschke et al, 1989;Martinez Soriano et al, 1990) and thyroid (Chakraborty et al, 1992;Ganguli et al, 1998) in mammals provide inextricable indices of the nature of activities of these glands.…”

Section: Discussionmentioning

confidence: 99%

“…Extensive studies have shown that in pineal and thyroid, an active phase, is characterized by increased nuclear size indicating stimulation of pineal and thyroid synthesis activity whereas inhibition of the pineal and thyroid is characterized by decreased nuclear size (Quay, 1965(Quay, , 1976Chakraborty & Maiti, 1981;Chakraborty & Maitra, 1982;Maiti & Chakraborty, 1982;Diehl et al, 1984;Sahu & Chakraborty, 1983, 1986Chaudhuri & Maiti, 1989;Hira et al, 1989;Peschke et al, 1989;Martinez Soriano et al, 1990;Chakraborty et al, , 1992Chakraborty, 1981Chakraborty, , 1993Chakraborty, , 1994Chakraborty & Sarkar, 1994;Ganguli et al, 1998Ganguli et al, , 2001Bandopadhyay et al, 2000).…”

Section: Histologymentioning

confidence: 99%

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Pineal-Thyroid Cytophysiological Responsiveness to Altered Steroid Hormone and Antihormone Milieu in Rat (Rattus rattus)

Sinha¹,

Chattopadhyay²,

2010

IJB

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The current investigation was undertaken to assess the pineal and thyroid gland cytophysiology and function in response to an exogenously altered steroid milieu following administration of a steroid hormone and non-steroidal antihormones. In the present study male rats (Rattus rattus) were injected with estradiol at a dose of 2 mg, testosterone 100 µg, tamoxifen 100 µg and flutamide 2 mg per 100 g b.w. intramuscularly for 15 consecutive days. Control rats were similarly injected with peanut oil vehicle intramuscularly for the same duration as the treated groups. The results indicated that pineal and thyroid gland response to estradiol and testosterone administration was opposite in nature. Estradiol induced significant hypertrophy of pineal and thyroid cytophysiology as indexed from significantly increased pineal and thyroid karyomorphological and associated parameter values, testosterone contrarily caused significant atrophy of pineal and thyroid cytophysiological parameters. Tamoxifen acted as a true estrogen agonist, whereas flutamide showed an androgen antagonist nature, thereby causing hyperactivity of pineal and thyroid karyomorphological and associated functions similar to that observed in estradiol treated rats, but contrary to that shown by testosterone induction in these rats.

Stimulatory response of pineal-thyroid nuclear morphology and function following adrenocortical modulation in rat (Rattus rattus)

Sinha¹,

Chattapadhyay²,

et al. 2009

Proc Zool Soc

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The relationship between pineal and thyroid in response to the adrenocortical modulation is poorly understood. In the present study post pubertal male rats were treated with natural and synthetic corticoids and an antiadrenal agent mitotane. Hydroxycortisone was administered at a dose of 4 mg / 100 g b.w., dexamethasone 2 mg / 100 g b.w. and mitotane 3 mg / 100 g b.w. for fifteen consecutive days. Our data revealed that both the corticoids, hydroxycorticosterone and dexamethasone induced hyperactivity of pineal and thyrofollicular cell morphology. The functional relation between the cells of the pineal parenchyma and thyroid follicles were noted. Similar results were induced by mitotane, an antiadrenal agent. It is concluded, that our present study indicates a mutual relationship between the pineal and the thyroid gland karyomorphological and functional parameters in response to corticoids and an antiadrenal agent in post pubertal male rat (Rattus rattus).