Long-term blood glucose monitoring with implanted telemetry device in conscious and stress-free cynomolgus monkeys

Abstract

Aims Continuous blood glucose monitoring, especially long-term and remote, in diabetic patients or research is very challenging. Nonhuman primate (NHP) is an excellent model for metabolic research, because NHPs can naturally develop Type 2 diabetes mellitus (T2DM) similarly to humans. This study was to investigate blood glucose changes in conscious, moving-free cynomolgus monkeys ( Macaca fascicularis ) during circadian, meal, stress and drug exposure. Materials and methods Blood glucose, body temperature and physical activities were continuously and simultaneously recorded by implanted HD-XG telemetry device for up to 10 weeks. Results and discussion Blood glucose circadian changes in normoglycemic monkeys significantly differed from that in diabetic animals. Postprandial glucose increase was more obvious after afternoon feeding. Moving a monkey from its housing cage to monkey chair increased blood glucose by 30% in both normoglycemic and diabetic monkeys. Such increase in blood glucose declined to the pre-procedure level in 30 min in normoglycemic animals and >2 h in diabetic monkeys. Oral gavage procedure alone caused hyperglycemia in both normoglycemic and diabetic monkeys. Intravenous injection with the stress hormones, angiotensin II (2 μg/kg) or norepinephrine (0.4 μg/kg), also increased blood glucose level by 30%. The glucose levels measured by the telemetry system correlated significantly well with glucometer readings during glucose tolerance tests (ivGTT or oGTT), insulin tolerance test (ITT), graded glucose infusion (GGI) and clamp. Conclusion Our data demonstrate that the real-time telemetry method is reliable for monitoring blood glucose remotely and continuously in conscious, stress-free, and moving-free NHPs with the advantages highly valuable to diabetes research and drug discovery.

Surgical removal of a telemetry system in a cynomolgus monkey (Macaca fascicularis): a 12-month observation study

“…Recently, various sensors or devices used to obtain physical data, cardiovascular effects, and blood glucose measurements have been developed and inserted into animal bodies for accurate and continuous testing results from a conscious, movement-free situation [ 2 , 7 , 8 ]. Most animals used in such studies are euthanized at the end of the study.…”

“…However, we need to consider whether euthanasia is the only effective and convenient method for the experimenter. When making the final judgment, we should take into account the scientific and ethical problems of reusing animals and obtain the opinions of the Institutional Animal Care and Use Committees (IACUC) committee members and make a final decision [ 7 , 8 ].…”

Histopathological analysis of zebrafish after introduction of non-biodegradable polyelectrolyte microcapsules into the circulatory system

“…Various blood parameters are usually considered reliable and comprehensive markers of the physiological state of any vertebrate organism ( Tahir et al, 2018 ; Bakke et al, 2020 ; Huang et al., 2019 ). Most current approaches require blood extraction to analyze its parameters; however, continuous real-time signal acquisition directly from an animal bloodstream has long been a desirable goal in physiological research ( Wang et al, 2017 ; Gray et al, 2018 ). A variety of recently developed molecular, nano- and microscale probes that may pass the information about blood parameters via optical, acoustic or magnetic signal ( Rong et al, 2019 ).…”

Re-Sterilisation of Single-Use Telemetric Devices

“…Telemetric transponder devices are designed to monitor and collect physiological data from conscious and freely moving animals of various species [1, 2]. Surgically implantable devices are able to measure vital parameters immediately and continuously within different fields of animal science such as cardiovascular, respiratory, or surgical studies [3].…”