Preferential saline or water intake by pinealectomized, adrenalectomized, and pinealectomized-adrenalectomized male rats.

Because the pineal gland appears to be involved in the regulation of body electrolytes, saline or water preference was investigated in pinealectomized, adrenalectomized, pinealectomized-adrenalectomized, and sham-operated (SO) control rats. The pinealectomized, adrenalectomized, and pinealectomized-adrenalectomized rats exhibited increased saline consumption during the two postoperative weeks when compared with the SO-control animals. Water intake was similar for pinealectomized and SO-control rats, but decreased for pinealectomized-adrenalectomized, and adrenalectomized rats. Although total fluid intake increased for pinealectomized, and pinealectomized-adrenalectomized rats, the proportion of saline ingested in preference to water by pinealectomized-adrenalectomized rats was twice that exhibited by pinealectomized rats. The results showed two different behaviors: increased saline intake without changes in water intake by pinealectomized rats, and increased saline intake with decreased water intake by adrenalectomized rats. However, the higher saline intake induced by pinealectomy was further increased by adrenalectomy, suggesting a direct role for the pineal gland in mediating specific salt appetite.