5-Aminolevulinic acid hydrochloride enhances bupivacaine-induced hypotension in spontaneously hypertensive rats

• Main Authors: Noboru Fukuda (Author), Mayumi Katakawa (Author), Hidenori Ito (Author), Takeshi Hara (Author), Noboru Otsuka (Author), Masahiro Ishizuka (Author), Masanori Abe (Author)
• Format: Book
• Published: Elsevier, 2023-05-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 1347-8613; 10.1016/j.jphs.2023.02.007
• Keywords: 5-Aminolevulinic acid; Hypotension; Bupivacaine; Propofol; Spontaneous hypertensive rats; Therapeutics. Pharmacology; RM1-950
• Source: Journal of Pharmacological Sciences, Vol 152, Iss 1, Pp 22-29 (2023)

Purpose: Oral administration of 5-aminolevulinic acid hydrochloride (5-ALA-HCl) has been reported to enhance the hypotensive effects associated with anesthetics, especially in elderly hypertensive patients treated with antihypertensive agents. The present study aimed to clarify the effects of antihypertensive-agent- and anesthesia-induced hypotension by 5-ALA-HCl in spontaneously hypertensive rats (SHRs). Methods: We measured blood pressure (BP) of SHRs and normotensive Wistar Kyoto (WKY) rats treated with amlodipine or candesartan before and after administration of 5-ALA-HCl. We also investigated the change in BP following intravenous infusion of propofol and intrathecal injection of bupivacaine in relation to 5-ALA-HCl administration. Findings: Oral administration of 5-ALA-HCl significantly reduced BP in SHRs and WKY rats with amlodipine and candesartan. Infusion of propofol significantly reduced BP in SHRs treated with 5-ALA-HCl. Intrathecal injection of bupivacaine significantly declined SBP and DBP in both SHRs and WKY rats treated with 5-ALA-HCl. The bupivacaine-induced decline in SBP was significantly larger in SHRs compared with WKY rats. Conclusion: These findings suggest that 5-ALA-HCl does not affect the antihypertensive agents-induced hypotensive effect, but enhances the bupivacaine-induced hypotensive effect, especially in SHRs, indicating that 5-ALA may contribute to anesthesia-induced hypotension via suppression of sympathetic nerve activity in patients with hypertension.