Morphology of the neural lobe of the hypophysis in rats treated with furosemide. II. Pituicytes.

Following three days of furosemide administration, the characteristics of the pituicytes in the neural lobe of the rat hypophysis were studied. The pituicytes of the animals which were treated with furosemide and had access to water during the treatment showed scarce cytoplasm organelles, conferring them with a clear appearance (light pituicytes), and a frequent finding was neurosecretory axons enclosed in their own cytoplasm. In the animals deprived of water during treatment, the pituicytes were dense (dark pituicytes) elongated, with a well-developed Golgi apparatus, numerous profiles of smooth endoplasmic reticulum and frequent annular gap junctions. It is concluded that the dehydration induced by the diuretic agent is the cause of the prevalence of the dark pituicytes.