# Border Biomedical Center Supplement: The impact of diet on the therapeutic, rewarding and adverse effects of morphine

> **NIH NIH U54** · UNIVERSITY OF TEXAS EL PASO · 2022 · $73,920

## Abstract

Project Summary
Opioid use disorder (OUD) and obesity are major comorbid public health concerns that are increasing
in national prevalence. OUD contributes to approximately 68% of all drug overdose deaths in the U.S.,
and obesity is a leading source of all-cause mortality. Patients diagnosed with obesity are also frequently
diagnosed with chronic pain conditions and are more likely to be prescribed opioids. Further, obesity is
highly prevalent among individuals with OUD, and is associated with higher risk for opioid overdose.
This suggests that individuals with obesity have an increased risk both of being prescribed opioid
analgesics and developing OUD; however, the physiological mechanisms that underlie these risks are
not well understood. Obesity is linked to the consumption of high fat diets; however, it is not known if
the risks related to OUD among patients diagnosed with obesity are due to this dietary history. This
RCMI pilot project proposal investigates the impact of diet on the therapeutic, rewarding, and adverse
effects of morphine, using behavioral and physiological assays in rats. Further, given recent evidence
suggesting that high fat, low carbohydrate ketogenic diets might have beneficial effects for obesity, the
proposed aims will also explore the effects of a ketogenic diet in addition to a low fat diet control
condition. To explore the impact of diet on sensitivity of rats to morphine, animal models of the
therapeutic effects of morphine (i.e., antinociception indexed via warm water tail withdrawal and von
Frey paw withdrawal assays) and reward (i.e., conditioned place preference and behavioral
sensitization) will be examined in Aim 1. Additionally, the adverse effects of morphine including
constipation (decreased gastrointestinal transit) and dependence (as measured by the presence or
absence of withdrawal symptoms following discontinuation or naloxone administration) will also be
explored in Aim 2 to mimic the experiences of patients taking opioids chronically for pain management
or recreational use. Finally, in Aim 3 this proposal will also evaluate changes in molecular markers within
specific brain regions associated with reward processing, feeding, and nociception, to identify targets
for future mechanism-driven assessments. These projects will provide a clear picture of the ways that
dietary history might impact the therapeutic effectiveness of opioids, as well as their abuse liability,
providing a translationally relevant assessment focused on two converging and increasing public health
concerns: obesity and OUD. These aims will also involve the training of underrepresented minority
scientists, including graduate and undergraduate students, and will serve to generate preliminary data
that will be used for future NIH grant proposals. The PI, an early-stage investigator and
underrepresented minority scientist, will also receive support through the Investigator Development
Core within the RCMI U54 Center at the University of...

## Key facts

- **NIH application ID:** 10560377
- **Project number:** 3U54MD007592-29S4
- **Recipient organization:** UNIVERSITY OF TEXAS EL PASO
- **Principal Investigator:** Robert A. Kirken
- **Activity code:** U54 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $73,920
- **Award type:** 3
- **Project period:** 1998-06-15 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10560377

## Citation

> US National Institutes of Health, RePORTER application 10560377, Border Biomedical Center Supplement: The impact of diet on the therapeutic, rewarding and adverse effects of morphine (3U54MD007592-29S4). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10560377. Licensed CC0.

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