Increased alpha 1B-adrenoreceptor mRNA levels in the rat kidney after thyroidectomy

Oligonucleotide probes were designed to sequences of the rat alpha 1B- and alpha 2B-adrenergic receptor mRNA and used for in situ hybridization histochemistry on tissue sections of kidneys from control and thyroidectomized rats. Both alpha 1B- and alpha 2B-receptor mRNA labelling was demonstrated in proximal tubule cells in the outer stripe of the outer medulla, with tubular rays radiating into the cortex. Thyroidectomy induced a more than 4-fold increase in mRNA for the alpha 1B-receptor in the kidney, whereas no change in alpha 2B-receptor mRNA levels could be demonstrated in thyroidectomized rats as compared to control animals. The results suggest that thyroid hormone plays an important role in regulating expression of alpha 1B-receptors in renal tubule cells.