The Effect of Pinealectomy on Plasma Vasopressin Response to Isotonic, Hypertonic and Hypovolemic Treatments in Rats Supplemented with L-Thyroxine


The present study was conducted to determine the effects of basal, isotonic as well as hypertonic and hypovolemic treatments on fluid-electrolyte balance and plasma AVP levels in rats supplemented with L-thyroxine and pinealectomized L-thyroxine. The animals were initially separated into 4 groups: control (n = 24), L-thyroxine treated (n = 24); L-thyroxine + sham-pinealectomy (n = 24) treated and 4-L-thyroxine + pinealectomy (n = 24) treated. L-thyroxine was given for 4 weeks. At the end of the 4-week experimental period, the sub-groups were formed before decapitation, which were classified as unstimulated (n = 6), isotonic (n = 6), hypertonic (n = 6) and hypovolemic (n = 6) stimulation. Plasma AVP, total triiodothyronine (TT3) and total thyroxine (TT4) levels were examined in plasma by RIA. Hematocrit and osmolality levels were also determined. It was found that the TT3 and TT4 levels showed significant increases in L-thyroxine treated groups (P < 0.001). Also, plasma AVP levels increased in the group subjected to L-thyroxine treatment. However, this increase was depicted to be significantly more prominent in L-thyroxine + pinealectomy treated group (P < 0.001). The results of the present study indicate that L-thyroxine treatment increases the basal and stimulated AVP release, which became more significant in the pinealectomy plus L-thyroxine treatment group. Moreover, the results indicate that AVP response to hypertonic and hypovolemic stimulations does not undergo any change due to supplementation by L-thyroxine treatment and/or pinealectomy plus L-thyroxine.


  1. 1.

    Ali, M., Guillon, G., Cantau, B., Balestre, M. N., Chicot, D., Clos, J. (1987) A. comparative study of plasma vasopressin levels and VI and V2 vasopressin receptor properties in congenital hypothyroid rat under thyroxine or vasopressin therapy. Horm. Metab. Res. 19, 624–628.

    CAS  Article  Google Scholar 

  2. 2.

    Baltaci, A. K., Mogulkoc, R., Bediz, C. S., Kul, A., Ugur, A. (2003) Pinealectomy and zinc deficiency have opposite effects on thyroid hormones in rats. Endocr. Res. 29, 473–481.

    Article  Google Scholar 

  3. 3.

    Baltaci, A. K., Mogulkoc, R., Bediz, C. S., Kul, A., Ugur, A. (2004) Opposite effects of zinc and melatonin on thyroid hormones in rats. Toxicology 195, 69–75.

    CAS  Article  Google Scholar 

  4. 4.

    Chiodera, P., Volpi, R., Capretti, L., Giuliani, N., Maffei, M. L., Coiro, V. (1998) Effect of melatonin on arginine vasopressin secretion stimulated by physical exercise or angiotensin II in normal men. Neuropeptide 32, 125–129.

    CAS  Article  Google Scholar 

  5. 5.

    Ciosek, J. (2002) Vasopressin and oxytocin release as influenced by thyrotropin-releasing hormone in euhydrated and dehydrated rats. J. Physiol. Pharmacol. 53, 423–437.

    CAS  PubMed  Google Scholar 

  6. 6.

    Ciosek, J., Drobnik, J. (2004) Vasopressin and oxytocin release and the thyroid function. J. Physiol. Pharmacol. 55, 423–441.

    CAS  PubMed  Google Scholar 

  7. 7.

    Coiro, V., Volpi, R., Caffarri, G., Capretti, L., Marchesi, C., Giacalone, G., Chiodera, P. (1997) Effect of melatonin on hypoglycemia and metoclopramide-stimulated arginine vasopressin secretion in normal men. Neuropeptides 31, 323–326.

    CAS  Article  Google Scholar 

  8. 8.

    Cowley, A. W. Jr, Skelton, M. M., Merrill, D. C. (1984) Long-term influence of vasopressin on the control of arterial blood pressure independent of volume changes. J. Hypertens. Suppl. 2, 337–339.

    CAS  Article  Google Scholar 

  9. 9.

    Dakine, N., Olier, C., Grio, M. (2000) Thyroxine modulates corticotropin-releasing factor but not arginine vasopressin gene expression in the hypothalamic paraventricular nucleus of the developing Rat. J. Neuroendocrinal. 12, 774–783.

    CAS  Article  Google Scholar 

  10. 10.

    Forsling, M. L., Stoughton, R., Kelestimur, H., Koistoglou-Athanassiou, I., Demaine, C. (1996) Release of vasopressin in response to altered plasma volume and sodium concentrations following pinealectomy in the rat. J. Pineal Res. 20, 211–216.

    CAS  Article  Google Scholar 

  11. 11.

    Forsling, M. L., Stoughton, R. P., Zhou, Y., Kelestimur, H., Demaine, C. (1993) The role of the pineal in the control of the daily patterns of neurohypophyseal hormone secretion. J. Pineal Res. 14, 45–51.

    CAS  Article  Google Scholar 

  12. 12.

    Hoffman, R. A., Reiter, R. J. (1965) Rapid pinealectomy in hamsters and other small rodents. Anat. Rec. 153, 19–21.

    CAS  Article  Google Scholar 

  13. 13.

    Isobe, Y., Torii, T., Nishino, H. (2001) Melatonin inhibits Arg-vasopressin release via MT(2) receptor in the suprachiasmatic nucleus-slice culture of rats. Brain Res. 889, 214–219.

    CAS  Article  Google Scholar 

  14. 14.

    Isobe, Y., Fujioi, J., Nishino, H. (2001) Orcadian rhythm of melatonin release in pineal gland culture: arg-vasopressin inhibits melatonin release. Brain Res. 918, 67–73.

    CAS  Article  Google Scholar 

  15. 15.

    Juszczak, M., Bojanowska, E., Dabroswki, R. (2000) Melatonin and the synthesis of vasopressin in pinealectomized rats. Proc. Soc. Exp. Biol. Med. 225, 207–210.

    CAS  Article  Google Scholar 

  16. 16.

    Juszczak, M., Kopotowska, A., Stempniak, B., Guzek, J. W. (1993) Hypothalamic and neurohypophyseal vasopressin and oxytocin content as influenced by haemorrhage in melatonin-treated male rats. Pathol. Pol. 44, 55–59.

    CAS  Google Scholar 

  17. 17.

    Juszczak, M., Stempniak, B., Guzek, J. W. (1992) Melatonin, pinealectomy, and release of neurohypophyseal hormones: in vitro studies. J. Pineal Res. 12, 1–6.

    CAS  Article  Google Scholar 

  18. 18.

    Konakchieva, R., Mitev, Y., Almeida, O. F., Patchev, V. K. (1997) Chronic melatonin treatment and the hypothalamo-pituitary-adrenal axis in the rat: attenuation of the secretory response to stress and effects on hypothalamic neuropeptide content and release. Biol. Cell. 89, 587–596.

    CAS  Article  Google Scholar 

  19. 19.

    Marcisz, C., Jonderko, G., Kucharz, E. J. (2001) Changes of plasma arginine-vasopressin level in patients with hyperthyroidism during treatment. Med. Sic. Monit. 7, 409–414.

    CAS  Google Scholar 

  20. 20.

    Mogulkoc, R., Baltaci, A. K., Yilmaz, B., Kelestimur, H. (1999) Influence of hypovolemic and hypertonic treatments on plasma vasopressin levels and fluid balance in the propylthiouracil-induced hypothyroid rat. Neuro Endocrinol. Lett. 20, 311–314.

    CAS  PubMed  Google Scholar 

  21. 21.

    Mogulkoc, R., Dogru, O., Baltaci, A. K., Yilmaz, B., Kelestimur, H. (2000) Influence of hypovolemic and hypertonic treatments on plasma vasopressin levels and fluid balance in the thyroidectomy-induced hypothyroid rats. Neuro Endocrinol. Lett., 21, 35–38.

    CAS  PubMed  Google Scholar 

  22. 22.

    Mogulkoc, R., Baltaci, A. K. (2006) Influences of isotonic, hypertonic and hypovolemic treatments on vasopressin response and fluid-electrolyte balance in L-thyroxine-induced hyperthyroid rat. Life Sci. 79, 817–821.

    CAS  Article  Google Scholar 

  23. 23.

    Riis, P. M., Madsen, A. (1985) Thyroxine concentrations and secretion rates in relation to pregnancy, lactation and energy balance in goats. J. Endocrinol. 107, 421–427.

    CAS  Article  Google Scholar 

  24. 24.

    Salomez-Granier, F., Lefebvre, J., Racadot, A., Dewailly, D., Linquette, M. (1983) Antidiuretic hormone levels (arginine-vasopressin) in cases of peripheral hypothyroidism. 26 cases. Presse Med. 12, 1001–1004.

    CAS  PubMed  Google Scholar 

  25. 25.

    Tohei, A., Watanabe, G., Taya, K. (1998) Hypersecretion of corticotropin-releasing hormone and arginine vasopressin in hypothyroid male rats as estimated with push-pull perfusion. J. Endocrinol. 156, 395–100.

    CAS  Article  Google Scholar 

  26. 26.

    Vargas, F., Baz, M. J., Luna, J. D., Andrade, J., Jodar, E., Haro, J. M. (1991) Urinary excretion of digoxin-like immunoreactive factor and arginine-vasopressin in hyper- and hypo-thyroid rats. Clin. Sci. (Lond). 81, 471–476.

    CAS  PubMed  Google Scholar 

  27. 27.

    Wiig, H., Reed, R. K., Tenstad, O. (2000) Interstitial fluid pressure, composition of interstitium, and interstitial exclusion of albumin in hypothyroid rats. Am. J. Physiol. Heart Circ. Physiol. 278, HI 627–1639.

    Article  Google Scholar 

  28. 28.

    Windle, R. J., Luckman, S. M., Stoughton, R. P., Forsling, M. L. (1996) The effect of pinealectomy on osmotically stimulated vasopressin and oxytocin release and Fos protein production within the hypothalamus of the rat. J. Neuroendocrinal. 8, 747–753.

    CAS  Article  Google Scholar 

  29. 29.

    Yasin, S. A., Costa, A., Besser, G. M., Hucks, D., Grossman, A., Forsling, M. L. (1993) Melatonin and its analogs inhibit the basal and stimulated release of hypothalamic vasopressin and oxytocin in vitro. Endocrinology 132, 1329–1336.

    CAS  Article  Google Scholar 

  30. 30.

    Zimmerman, R. S., Ryan, J., Edwards, B. S., Klee, G., Zimmerman, D., Scott, N., Burnett, J. C. Jr. (1988) Cardiorenal endocrine dynamics during volume expansion in hypothyroid dogs. Am. J. Physiol. 255, R. 61–66.

    Google Scholar 

Download references


This study was supported by Scientific Research Projects Coordinatorship of Selcuk University (SUBAPK). (Project No: TF 2002/089). Authors would like to thanks Dr. Esma Oztekin for hormones analysis.

Author information



Corresponding author

Correspondence to R. Mogulkoc.

Rights and permissions

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Reprints and Permissions

About this article

Cite this article

Mogulkoc, R., Baltaci, A.K. The Effect of Pinealectomy on Plasma Vasopressin Response to Isotonic, Hypertonic and Hypovolemic Treatments in Rats Supplemented with L-Thyroxine. BIOLOGIA FUTURA 59, 163–172 (2008).

Download citation


  • AVP
  • L-thyroxine treatment
  • pinealectomy
  • hypertonic and hypovolemic stimulation
  • osmolality
  • rat