Recovery of p-Ca2+ from hypocalcemia resulted in lower levels in NX-TPTX than in TPTX rats, 1.20 ± 0.02 vs.1.30 ± 0.02 (p < 0.05) demonstrating that absence of kidneys significantly affected the rapid regulation of p-Ca2+ independent of PTH, C-PTH and CT. Here, CALCA is linked to Hypocalcemia.