oxytocin and Kidney-Neoplasms

Renal cell carcinoma has been reported to contain estrogen and progesterone receptors. Thus, it has been suggested that these tumors are hormone dependent in a similar manner described for the breast and prostate cancers. It has been recently shown that mammary and prostate tumor cells contain gonadotropin-releasing hormone (GnRH) receptors and are growth inhibited directly by GnRH antagonists. In this study we examined for the presence of GnRH, estrogen and progesterone receptors in normal and malignant renal tissues. Estrogen receptors were found both in the normal and malignant kidney while progesterone receptors were present only in the normal tissue. Specific binding of [125I]buserelin, a GnRH agonist, was evident in renal carcinoma and in normal kidney and was displaced with equal efficiency by unlabeled buserelin and by D-Trp6-GnRH, but not by unrelated peptides such as thyrotropin releasing hormone and oxytocin. The non-linear scatchard curve obtained for buserelin binding, suggests the presence of at least two binding sites, one with high affinity in the nanomolar range and another in the micromolar range.

Topics: Buserelin; Carcinoma, Renal Cell; Cytosol; Humans; Kidney; Kidney Neoplasms; Oxytocin; Receptors, Estrogen; Receptors, LHRH; Receptors, Progesterone; Thyrotropin-Releasing Hormone

The arterial blood flow distribution between tumour and intact renal tissue was investigated in rats with transplanted sarcomas. Changes in tissue flow were measured by the microsphere tracer technique, and the redistributing effects on blood flow of vasopressin, noradrenalin and oxytocin was recorded. Bolus injections of vasopressin gave a transient decrease of intact tissue flow, not found in tumours. At increasing doses of vasopressin and in early tumour growth phase, the flow discriminating effect tended to vanish. Constant intravenous infusion of vasopressin gave similar reduction of flow in tumour and intact tissue. Selective administration into the renal artery reduced flow in intact tissue but produced ambiguous effects in tumour tissue. Noradrenalin produced less reduction of tumour flow as compared with intact tissue flow. Oxytocin increased tumour blood flow while no flow change occurred in intact tissue. Oxytocin thus appeared to produce the most favourable redistribution of flow within tumour kidneys for the prospect of conveying cytotoxic agents selectively to the tumour.

Topics: Animals; Female; Kidney; Kidney Neoplasms; Male; Norepinephrine; Oxytocin; Rats; Regional Blood Flow; Sarcoma, Experimental; Vasopressins