Saline and water intake in the bromocriptine-treated hybrid of spontaneously hypertensive and normotensive rats

Abstract

The effects of a 13-day intraperitoneal infusion of bromocriptine or vehicle delivered by osmotic pumps on blood pressure, plasma and pituitary prolactin have been previously reported in the segregating F 2 generation of the hybrid of the spontaneously hypertensive rat and the Wistar-Kyoto rat. The F 2 rats were divided into three groups, each with a mean systolic blood pressure as follows - group I: 134 mmHg; group II: 152 mmHg and group III: 171 mmHg. This paper reports further on that study in describing the changes in saline and water intakes in these rats. Bromocriptine was found to have no significant effect on saline intake in group I and group II rats but significantly increased saline intake in group III rats. Bromocriptine had no significant effect on water intake in group I and III rats but significantly increased water intake in group II rats. In contrast to the earlier result with prolactin, these results suggest that saline and water intakes are not related to systolic blood pressure. The mechanisms that influence these also appear to be different.