BACKGROUNDS: L-type voltage-dependent calcium channel (LTCC) plays a crucial role in insulin secretion from pancreatic beta cells through Ca2+ influx. In the recent report, LTCC Ca(v)1.3 subtype homozygous knock out mice showed impairment of postnatal pancreatic beta cell development as well as insulin secretion. METHODS: We performed 90% partial pancreatectomy in heterozygous Ca(v)1.3 knock out mice to investigate the effect of partial deficiency of Ca(v)1.3 gene on beta cell regeneration in the adult. Glucose homeostasis, metabolic profiles including serum insulin and lipid levels and morphologic changes of pancreatic islets were studied. RESULTS: 90% Partial pancreatectomy induced glucose intolerance only in the heterozygous knock out mice at 8 weeks after surgery. Distribution of islet size was significantly different between two groups after partial pancreatectomy; median value of islet size of heterozygote was larger than that of wild type (642.8 micrometer2 vs 1459.8 micrometer2, P < 0.01). The frequency of single beta cell unit, considered as a unit of beta cell neogenesis, was much lower in heterozygote than that of wild type (41% vs 23.3%, P < 0.05). CONCLUSION: These data suggest that Ca(v)1.3 gene deficiency is specifically associated with impairment of beta cell regeneration, especially neogensis and eventual glucose intolerance in the 90% partial pancreatectomized mice.