Parathyroid cells express Ca²⁺-conducting currents that are activated by raising the extracellular Ca²⁺ concentration ([Ca²⁺]_o). We investigated the sensitivity of these currents to dihydropyridines, the expression of voltage-dependent Ca²⁺ channel (VDCC) subunits, and the effects of dihydropyridines on the intracellular free [Ca²⁺] ([Ca²⁺]_i) and secretion in these cells. Dihydropyridine channel antagonists dose dependently suppressed Ca²⁺-conducting currents, and agonists partially reversed the inhibitory effects of the antagonists in these cells. From a bovine parathyroid cDNA library, we isolated cDNA fragments encoding parts of an _1S- and a ₃-subunit of L-type Ca²⁺ channels. The _1S-subunit cDNA from the parathyroid represents an alternatively spliced variant lacking exon 29 of the corresponding gene. Northern blot analysis and immunocytochemistry confirmed the presence of transcripts and proteins for ₁- and ₃-subunits in the parathyroid gland. The addition of dihydropyridines had no significant effects on high [Ca²⁺]_o-induced changes in [Ca²⁺]_i and parathyroid hormone (PTH) release. Thus our studies indicate that parathyroid cells express alternatively spliced L-type Ca²⁺ channel subunits, which do not modulate acute intracellular Ca²⁺ responses or changes in PTH release.