RELEASE OF VASOPRESSIN DURING SUPPRESSION OF OESTROUS CYCLE IN RAT BY ZOLADEX AND HYPOVOLEMIC CHALLENGE

Salma Aslam Kundi, Saleem Wazir, Saleem Afzal, Naeema Afzal, Iftikhar Qayum, Mary L. Forsling

Abstract


Background: The vasopressin (AVP) response to hypovolemia has been compared in intact and
chemically castrated rats. This functional ovariectomy was done to confirm the findings in surgical
ovariectomy of how gonadal steroids modulate the release of AVP under hypo-volemic challenge.
Methods: Twenty female Sprague Dawley rats were checked for oestrous over two consecutive
cycles. The ten control rats were given sub-cutaneous puncture only whereas the experimental
were given Zoladex implant. On the fifteenth day all the rats were given intra-peitoneal injection
of poly-ehylene glycol. All the rats were de-capitated after an hour. Results: The uterine weight
was significantly decreased in experimental group. The plasma AVP level was also significantly
decreased in the experimental group. The pituitary AVP level was significantly increased in the
experimental group. Conclusion: The chemical castration effected the AVP secretion, this proves
that the sex steroids modulate the release of AVP secretion inspite of hypo-volemic challenge.
Keywords: Zoladex, Hypovolemia, Vasopressin

Full Text:

PDF

References


Van Leeuwen FW, Pool CW, Sluiter AA. Enkephalin

immunoreactivity in synaptoid elements on glial cells in

the rat neural lobe. Neuroscience 1983;8:229-41.

Bicknell RJ, Chapman C, Zhao BG. Opiod receptor

subtypes mediating inhibition of oxytocin, vasopressin and

noradrenaline release from the neurohypophysis in vitro. J

Physiol 1987;388:9.

Swachenko P, Swanson LW. The organisation of

noradrenergic pathways from the brain stem to the

paraventricullar and supraoptic nuclei in the rat. Brain

Research Review 1982;4:275-325.

Sladek CD. Vasopressin response to osmotic and

hemodynamic stress: neurotransmitter involvement. Stress

; 7(2): 85-90.

Dunn FL, Brennen TJ, Nelson AE, Robertson GL. The

role of blood osmolality and volume in regulating

vasopressin secretion in the rat. J Clin Invest

;52:3212-9.

Butcher RL, Collins WE, Fugo NW. Plasma

concentrations of LH, FSH prolactin, progesterone and

oestradiol 17 B throughout the 4 day oestrous cycle of the

rat. Endocrinology 1974;94:1704-7.

De Varies GJ, Buijis RM, Sluiter AA. Gonadal hormone

action on the morphology of the vasopressingergic

innervation of the adult rat brain. Brain Research

;298:141-5.

Kondo N, Arima H, Banno R, Kuwahara S, Sato I, Oiso

Y. Osmoregulation of vasopressin release and gene

transcription under acute and chronic hypovolemia in rats.

Am J Physiol Endocrinol Metab 2004; 286(3):E 337–46.

Hussain MK, Manger WM, Rock TW, Weiss RJ, Frantz

AG. Vasopressin release due to manual restraint in the rat:

role of body compression and comparison with other with

other stressful stimuli. Endocrinology 1979;104:641-4.

Barron WM, Stamoutson BA, Lindheimer MD. Role of

volume in regulation of vasopressin secretion during

pregnancy in the rat. J Clinic Invest 1984;73:923–32.

Barron WM, Schreiber J, Lindheimer MD. Effect of

ovarian sex steroids on osmoregulation and vasopressin

secretion in the rat. Endocrine Metab. Am J Physiol 1986;

: E352–E361

Zhou Y, Forsling ML. Effect of reproductive status on

plasma oxytocin concentrations and the renal response to

oxytocin in the conscious rat. Exp Physiol 2000;85(1):73-

Hartley DE, Dickson SL, Forsling ML. Plasma

vasopressin concentrations and Fos protein expression in

the supraoptic nucleus following osmotic stimulation or

hypovolaemia in the ovariectomized rat: effect of

oestradiol replacement. J Neuroendocrinol 2004; 16(3):

-20


Refbacks

  • There are currently no refbacks.


Contact Number: +92-992-382571

email: [jamc] [@] [ayubmed.edu.pk]