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Similar Effects of Type 1 Diabetes on the Pressor Reflex in Male and Female Rats
Author(s) -
Grotle AnnKatrin,
Garcia Elizabeth A.,
Stone Audrey J
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.712.11
Subject(s) - medicine , ctl* , endocrinology , streptozotocin , mean arterial pressure , diabetes mellitus , blood pressure , heart rate , antigen , cd8 , immunology
Type 1 diabetes (T1DM) pathophysiology and prevalence differ in males as do the mechanisms of cardiovascular related diseases. The purpose of this study was to establish whether the pressor and cardioaccelerator responses evoked by static contraction or tendon stretch differ by sex in T1DM rats. We injected (i.p) 50 mg/kg of Streptozotocin (STZ) or the vehicle (CTL) i.p. in either sex and waited 1wk (female CTL: BW=267±5 g, glucose=195±10 mg/dl, HbA1C=4.5±0.8%; male CTL: BW=360±12 g, glucose=361±12 mg/dl, HbA1C=4.4±0.1%; female STZ: BW=254±12 g, glucose=495±29 mg/dl, HbA1C=6.3±0.2%; male STZ: BW=273±16 g, glucose=408±29 mg/dl, HbA1C=6.5±0.5%;) or 3wks (female CTL: BW=286±6 g, glucose=177±28 mg/dl, HbA1C=4.3±0.1%; %; male CTL: BW=427± g, glucose=238±36 mg/dl, HbA1C=5.1±0.7%; female STZ: BW=274±15 g, glucose=503±37 mg/dl, HbA1C=9.2±0.6%; male STZ: BW=306±11 g, glucose=436±26 mg/dl, HbA1C=10.7±0.2) before performing experiments. In unanaesthetized, decerebrate rats, we statically contracted the hindlimb muscles or stretched the Achilles tendon for 30s and measured changes in mean arterial pressure (MAP) and heart rate (HR). We found that the pressor (female CTL: ΔMAP=19±12 mmHg, n=4; male CTL: ΔMAP=21±4 mmHg, n=5; female STZ: ΔMAP=50±18 mmHg, n=3; male STZ: ΔMAP=49±12 mmHg, n=3, p=0.99) and cardioaccelerator (female CTL: ΔHR=8±2 bpm, n=4; male CTL ΔHR=10±3 bpm, n=5; female STZ: ΔHR=10±1 bpm, n=3; male STZ: ΔHR=23±5.1 bpm n=3, p=0.25) responses to tendon stretch were not significantly different between sexes 1wk after STZ injection. Likewise, the pressor (female CTL: ΔMAP=15±2 mmHg, n=6; male CTL: ΔMAP=23±5 mmHg, n=3; female STZ: ΔMAP=35±8 mmHg, n=5; male STZ: ΔMAP=27±5 mmHg, n=3, p=0.18) and cardioaccelerator (female CTL: ΔHR=16±2 bpm, n=6; male CTL: ΔHR=12±6 bpm, n=3; female STZ: ΔHR=16±8 bpm, n=6; male STZ: ΔHR=27±10 bpm, n=3, p=0.25) responses to static contraction were not different between sexes 3wks after STZ injection. Furthermore, the pressor (female CTL: ΔMAP=21±4 mmHg, n=5; male CTL: ΔMAP=55±4 mmHg, n=3; female STZ: ΔMAP=30±11 mmHg, n=5; male STZ: ΔMAP=30±11 mmHg, n=6, p=0.45) and cardioaccelerator (female CTL: ΔHR=9±3 bpm, n=5; male CTL: ΔHR=17±3 bpm, n=3; female STZ: ΔHR=14±8 bpm, n=5; male STZ: ΔHR=12±3 bpm, n=6, p=0.3) responses to tendon stretch were not significantly different between sexes 3wks after STZ injection. The developed tensions from contraction or tendon stretch were similar within each comparison. We conclude that the pressor and cardioaccelerator responses to tendon stretch and static contraction are not different between male and female rats in either the beginning or later stage of T1DM.